Articles tagged as "Philippines"

Technology for tuberculosis, but why can’t we simply prevent it with proven tools that save lives?

Editor’s notes: Advances in diagnostic test technology have transformed the management of HIV and related infections.  For HIV, we have seen the introduction of self-administered test kits as well as new approaches to HIV viral load testing and nucleic acid based infant diagnosis.  Cryptococcal antigen screening can make prophylaxis and treatment more focused and potentially cost-effective.  For tuberculosis the biggest revolution has been the widespread introduction of the geneXpert® system.  The newest version, the Xpert® Ultra, is more sensitive than the original cartridge and is now being scaled up in countries including South Africa.  Agizew and colleagues conducted a study in Botswana to compare how the Xpert® MTB/RIF cartridge performed when used in centralized or peripheral health facilities.  Encouragingly there were few differences between the two levels, suggesting that the systems can be used close to the point of care.  However, the authors did note a surprisingly high level of unsuccessful tests (15%) both at the central lab and at the peripheral clinic.  Many of these test failures seem to have been because the sample was not processed correctly, and so should be amenable to better training for the health care workers performing the test.  The yield of testing varied greatly between the 13 sites. Between 1% and 23% of samples were positive for tuberculosis, with an average of 14%.  This may be because some sites were receiving specialized referrals.  Of the 447 positive samples, 8% were shown to be rifampicin resistant.  This figure is hard to interpret without more detail of the sample of patients in whom the test was performed.  Resistance is always higher among those who have been treated previously and may be higher in those referred to specialized centres.  Nonetheless, it demonstrates that there are a significant number of people with tuberculosis in Botswana who are very likely to have multi-drug resistant disease and need effective second line treatment.  Technology comes with a price tag.  In this study, the team bought test kits for $18 each, which makes it an expensive choice.  However, if it leads to prompt treatment of multi-drug resistant disease and more accurate diagnosis of tuberculosis, including among those living with HIV, this might still be cost-effective.

A small implementation research study from a single provincial referral centre in Zambia also examined the use and results of geneXpert® screening.  Masenga and colleagues found that 6.6% of 2374 samples tested by geneXpert® over the course of a year were positive for tuberculosis.  An additional 1301 samples were tested by sputum microscopy.  Their results suggest that geneXpert® was used mainly on people who were living with HIV, given that more than 90% of the positive samples came from people living with HIV.  5.9% of the 152 positive samples that were tested in the system were resistant to rifampicin, with no difference by gender.  This study leaves many questions unanswered, such as the sampling strategy, the history of previous treatment and the outcomes of the diagnosis in terms of treatment regimen and success.  However, it shines a light on the ways that new technology is now routine in some settings.  We need more research from diverse settings to paint the full picture of implementation outside traditional research centres.

Zenner and colleagues revisit the question of the risks and benefits of treatment for latent tuberculosis infection.  In a systematic review and network meta-analysis, they demonstrate once more that we have several effective ways to prevent tuberculosis among people living with HIV and that the harms are much smaller than the risks.  The question remains why we have failed so badly to scale up preventive therapy for tuberculosis alongside the success in scale up of antiretrovirals.

 

Peripheral clinic versus centralized laboratory-based XPERT® MTB/RIF performance: experience gained from a pragmatic, stepped-wedge trial in Botswana

Agizew T, Boyd R, Ndwapi N, Auld A, Basotli J, Nyirenda S, Tedla Z, Mathoma A, Mathebula U, Lesedi C, Pals S, Date A, Alexander H, Kuebrich T, Finlay A. PLoS One. 2017 Aug 17;12(8):e0183237. doi: 10.1371/journal.pone.0183237. eCollection 2017.

Background: In 2011, the Botswana National Tuberculosis Program adopted World Health Organization guidelines and introduced Xpert® MTB/RIF (Xpert®) assay to support intensified case finding among people living with HIV enrolling in care. An evaluation was designed to assess performance under operational conditions to inform the national Xpert® scale-up.

Methods: Xpert® was implemented from August 2012 through November 2014 with 13 GeneXpert® instruments (GeneXpert®) deployed in a phased approach over nine months: nine centralized laboratory and four point-of-care (POC) peripheral clinics. Clinicians and laboratorians were trained on the four-symptom tuberculosis screening algorithm and Xpert® testing. We documented our experience with staff training and GeneXpert® performance. Test results were extracted from GeneXpert® software; unsuccessful tests were analysed in relation to testing sites and trends over time.

Results: During 276 instrument-months of operation a total of 3630 tests were performed, of which 3102 (85%) were successful with interpretable results. Mycobacterium tuberculosis complex was detected for 447 (14%); of these, 36 (8%) were rifampicin resistant. Of all 3630 Xpert® tests, 528 (15%) were unsuccessful; of these 361 (68%) were classified as "error", 119 (23%) as "invalid" and 48 (9%) as "no result". The total number of recorded error codes was 385 and the most common reasons were related to sample processing (211; 55%) followed by power supply (77; 20%) and cartridge/module related (54; 14%). Cumulative incidence of unsuccessful test was similar between POC (17%, 95% CI: 11-25%) and centralized laboratory-based GeneXpert® instruments (14%, 95% CI: 11-17%; p = 0.140).

Conclusions: Xpert® introduction was successful in the Botswana setting. The incidence of unsuccessful test was similar by GeneXpert® location (POC vs. centralized laboratory). However, unsuccessful test incidence (15%) in our settings was higher than previously reported and was mostly related to improper sample processing. Ensuring adequate training among Xpert® testing staff is essential to minimize errors.

Abstract  Full-text [free] access

Rifampicin resistance in mycobacterium tuberculosis patients using GeneXpert® at Livingstone Central Hospital for the year 2015: a cross sectional explorative study

Masenga SK, Mubila H, Hamooya BM. BMC Infect Dis. 2017 Sep 22;17(1):640. doi: 10.1186/s12879-017-2750-9

Background: Since the recent introduction of GeneXpert® for the detection of Tuberculosis (TB) drug resistance mutations in both primary resistance and acquired resistance in Zambia, little has been documented in literature on the issue of rifampicin resistance especially in the face of a high National TB burden. The study aimed to determine the prevalence of rifampicin resistance in tuberculosis patients at Livingstone Central Hospital for the year 2015.

Methods: This was a cross sectional study conducted at Livingstone Central Hospital where we reviewed 152 records (from January 1, 2015 to 31st December 2015) involving patients who presented with clinically suspected TB or documented TB, whose samples were sent to the laboratory for GeneXpert® Mycobacterium tuberculosis/rifampicin testing. Statistical evaluations used a one-sample test of proportion and Fisher's exact test.

Results: The age of participants ranged from 8 months to 73 years old (median = 34). Of the participants with complete data on gender, 99 (66%) and 52 (34%) were males and females respectively. The TB co-infection with HIV prevalence was 98.3% (p < 0.001). Prevalence of rifampicin resistance was 5.9% and there was no statistical significant difference between being male or female (p = 0.721).

Conclusion: We were able to show from our study, evidence of rifampicin resistance at Livingstone Central Hospital. Hence, there was need for further in-depth research and appropriate interventions (i.e. close follow-up and patient care for drug resistance positive patients).

Abstract  Full-text [free] access

Treatment of latent tuberculosis infection: an updated network meta-analysis

Zenner D, Beer N, Harris RJ, Lipman MC, Stagg HR, van der Werf MJ.  Ann Intern Med. 2017 Aug 15;167(4):248-255. doi: 10.7326/M17-0609. Epub 2017 Aug 1.

Background: Treatment of latent tuberculosis infection (LTBI) is an important component of tuberculosis (TB) control, and this study updates a previous network meta-analysis of the best LTBI treatment options to inform public health action and programmatic management of LTBI.

Purpose: To evaluate the comparative efficacy and harms of LTBI treatment regimens aimed at preventing active TB among adults and children.

Data sources: PubMed, Embase, and Web of Science from indexing to 8 May 2017; clinical trial registries; and conference abstracts. No language restrictions were applied.

Study selection: Randomized controlled trials that evaluated human LTBI treatments and recorded at least 1 of 2 prespecified end points (hepatotoxicity and prevention of active TB).

Data extraction: 2 investigators independently extracted data from eligible studies and assessed study quality according to a standard protocol.

Data synthesis: The network meta-analysis of 8 new and 53 previously included studies showed that isoniazid regimens of 6 months (odds ratio [OR], 0.65 [95% credible interval {CrI}, 0.50 to 0.83]) or 12 to 72 months (OR, 0.50 [CrI, 0.41 to 0.62]), rifampicin-only regimens (OR, 0.41 [CrI, 0.19 to 0.85]), rifampicin-isoniazid regimens of 3 to 4 months (OR, 0.53 [CrI, 0.36 to 0.78]), rifampicin-isoniazid-pyrazinamide regimens (OR, 0.35 [CrI, 0.19 to 0.61]), and rifampicin-pyrazinamide regimens (OR, 0.53 [CrI, 0.33 to 0.84]) were efficacious compared with placebo. Evidence existed for efficacy of weekly rifapentine-isoniazid regimens compared with no treatment (OR, 0.36 [CrI, 0.18 to 0.73]). No conclusive evidence showed that HIV status altered treatment efficacy.

Limitation: Evidence was sparse for many comparisons and hepatotoxicity outcomes, and risk of bias was high or unknown for many studies.

Conclusion: Evidence exists for the efficacy and safety of 6-month isoniazid monotherapy, rifampicin monotherapy, and combination therapies with 3 to 4 months of isoniazid and rifampicin.

Abstract  Full-text [free] access

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Some key considerations for surveys of key populations

Editor’s notes: A key challenge for epidemiological research involving key populations is to find a representative sample.  Whereas national surveys such as demographic health surveys (DHS) and PHIA can use the total population to create a sampling frame from which to draw individuals at random, researchers interested in key populations have to use a range of methods, all of which have limitations as well as strengths.  Internet and app-based surveys may accrue large numbers, but may have significant biases in terms of who chooses to answer such questionnaires.  Venue-based sampling allows data to be collected from people who happen to be at the venue at the same time as the researchers.  Respondent driven sampling has become increasingly popular as a method to reach individuals that might otherwise be hard to include in studies.  Increasingly sophisticated statistical methods have been developed to adjust estimates, and in particular their precision, according to characteristics of respondents found in the sample.

This month we have three respondent driven studies that highlight different methodological aspects as well as shedding light on key populations in Africa and Asia.  Hladik et al. conducted a major survey of female sex workers in Kampala, Uganda.  Unfortunately, it has taken some time for this study to be published, as the original questionnaires were completed in 2008/9 and it is plausible that many aspects of sex work have been changing over the past decade.  Nonetheless, the authors succeeded in enrolling almost 1000 female sex workers from the capital city using a respondent driven sampling approach.  The authors paid close attention to methods that could maximize the validity of the data they collected as well as ensuring that participants were protected.  Formative research laid out acceptable incentives to participate, as well as approaches to discuss sensitive or taboo areas and to ensure that all the women understood what was being asked in particular questions.  Finger scanners were used to generate unique identification numbers, so that women could be tracked during the study, and these files were subsequently deleted.  This approach was widely accepted, as it has been in many programmes offering services that benefit from a linked identifier.  However, any approach that creates identifiers for populations that are often discriminated or legislated against needs to be examined critically to ensure that any risks to participants are well understood, particularly for research that is not going to bring any direct benefits to the individual participants.  Although the study’s findings are not particularly surprising, they remind us that sex workers in Kampala need to remain a vital part of the HIV response.  Not only are they affected by a high prevalence of 33%, rising to 44% among those over 25 years old, but they are also subject to horribly high rates of violence including both rape and beating in up to one third of the women in the one month prior to the interview.  The study highlights particular factors that might help identify women in most need of HIV and other services.  Women with less education, who rely entirely on sex work for their income and who have never tested for HIV are all more likely to be HIV positive.

In nearby Malawi, Wirtz et al. point out that many respondent driven samples of key populations, such as that from Hladik et al., are only able to collect data from one particular city or region, and that this can lead to misinterpretation if the results are generalized to whole countries.  The authors conducted a large study of gay men and men who have sex with men in seven different communities across Malawi.  They found considerable heterogeneity leading to an overall estimate that the risk of HIV was approximately twice as high in gay men and men who have sex with men as in the general population of men of the same age.  The study managed to enrol a total of almost 2500 men through respondent driven sampling in the different districts.  However, this was at the expense of having to collect data over a considerable time period, with the study team moving from district to district.  As the authors acknowledge, the risk is that data collected in the most recent time period may not be equivalent to data collected four years previously.  The authors did find that the highest rates of HIV among gay men and men who have sex with men were not always where they have been presumed to be.  In particular tourist areas and some rural areas had higher rates than some of the cities that are usually the focus of key populations programmes.  Once again, the finding that so few gay men and men who have sex with men knew their status and were linked to treatment may not be surprising but is still shocking.  Only 1% of men found to be positive reported that they were aware of their status.  The authors point out the tension between public health and policy in a country where homosexuality is criminalized.  If HIV is to be prevented, this tension will need to be resolved.

The third respondent driven sampling study also highlights heterogeneity.  Verdery et al. used additional statistical methods to study the network characteristics of people who use drugs in two cities in the Philippines (Cebu and Mandaue).  The “small world” phenomenon explains how in more closed settings everyone knows everyone else, and among people who use drugs, many people form part of overlapping networks of needle sharing that allow for rapid propagation of infection.  Developing such methods could allow respondent driven samples to yield greater insights in to the epidemiology of HIV in key populations.  However, issues of representation both of the sample interviewed and of the broader geographic population of interest will remain important.  Quantitative research is certainly essential to understand the population sizes of key populations, and their prevalence, incidence and risk factors of HIV infection.  However, research into policy formation; social science research to understand the larger context of HIV and implementation science to determine how better to offer services that engage individuals in HIV testing and care remain a high priority. 

Burden and characteristics of HIV infection among female sex workers in Kampala, Uganda - a respondent-driven sampling survey

Hladik W, Baughman AL, Serwadda D, Tappero JW, Kwezi R, Nakato ND, Barker J. BMC Public Health. 2017 Jun 10;17(1):565. doi: 10.1186/s12889-017-4428-z.

Background: Sex workers in Uganda are at significant risk for HIV infection. We characterized the HIV epidemic among Kampala female sex workers (FSW).

Methods: We used respondent-driven sampling to sample FSW aged 15+ years who reported having sold sex to men in the preceding 30 days; collected data through audio-computer assisted self-interviews, and tested blood, vaginal and rectal swabs for HIV, syphilis, neisseria gonorrhea, chlamydia trachomatis, and trichomonas vaginalis.

Results: A total of 942 FSW were enrolled from June 2008 through April 2009. The overall estimated HIV prevalence was 33% (95% confidence intervals [CI] 30%-37%) and among FSW 25 years or older was 44%. HIV infection is associated with low levels of schooling, having no other work, never having tested for HIV, self-reported genital ulcers or sores, and testing positive for neisseria gonorrhea or any sexually transmitted infections (STI). Two thirds (65%) of commercial sex acts reportedly were protected by condoms; one in five (19%) FSW reported having had anal sex. Gender-based violence was frequent; 34% reported having been raped and 24% reported having been beaten by clients in the preceding 30 days.

Conclusions: One in three FSW in Kampala is HIV-infected, suggesting a severe HIV epidemic in this population. Intensified interventions are warranted to increase condom use, HIV testing, STI screening, as well as antiretroviral treatment and pre-exposure prophylaxis along with measures to overcome gender-based violence.

Abstract  Full-text [free] access

 

Geographical disparities in HIV prevalence and care among men who have sex with men in Malawi: results from a multisite cross-sectional survey.

Wirtz AL, Trapence G, Kamba D, Gama V, Chalera R, Jumbe V, Kumwenda R, Mangochi M, Helleringer S, Beyrer C, Baral S. Lancet HIV. 2017 Jun;4(6):e260-e269. doi: 10.1016/S2352-3018(17)30042-5. Epub 2017 Feb 28.

Background: Epidemiological assessment of geographical heterogeneity of HIV among men who have sex with men (MSM) is necessary to inform HIV prevention and care strategies in the more generalised HIV epidemics across sub-Saharan Africa, including Malawi. We aimed to measure the HIV prevalence, risks, and access to HIV care among MSM across multiple localities to better inform HIV programming for MSM in Malawi.

Methods: Between Aug 1, 2011, and Sept 13, 2014, we recruited MSM into cross-sectional research via respondent-driven sampling (RDS) in seven districts of Malawi. RDS and site weights were used to estimate national HIV prevalence and engagement in care and in multilevel regression models to identify correlates of prevalent HIV infection. The comparative prevalence ratio of HIV among MSM relative to adult men was calculated by use of direct age-stratification.

Findings: 2453 MSM were enrolled with a population HIV prevalence of 18·2% (95% CI 15·5-21·2), as low as 4·1% (2·2-7·6) in Mzuzu and as high as 24·5% (19·5-30·3) in Mulanje. The comparative HIV prevalence ratio was 2·52 when comparing MSM with the adult male population. Age-stratified HIV prevalence showed early onset of infection with 11·8% (95% CI 7·3-18·4) of MSM aged 18-19 years HIV infected. Factors positively associated with HIV infection included being aged 21-30 years and reporting female or transgender identity. Among HIV infected MSM, less than 1% reported ever being diagnosed with HIV infection (0·9%, 95% CI 0·4-2·5) and initiated antiretroviral treatment (0·2%, 0·2-0·3).

Interpretation: HIV disproportionately affects MSM in Malawi with disparities sustained across the HIV care continuum. These issues are geographically heterogeneous and begin among young MSM, supporting geographically focused and age-specific approaches to confidential HIV testing with linkage to HIV services. 

Abstract access 

 

Social network clustering and the spread of HIV/AIDS among persons who inject drugs in two cities in the Philippines

Verdery AM, Siripong N, Pence BW. J Acquir Immune Defic Syndr. 2017 Sep 1;76(1):26-32. doi: 10.1097/QAI.0000000000001485. Epub 2017 Jun 22.

Introduction: The Philippines has seen rapid increases in HIV prevalence among people who inject drugs. We study two neighboring cities where a linked HIV epidemic differed in timing of onset and levels of prevalence. In Cebu, prevalence rose rapidly from under 1% to 54% between 2009 and 2011 and remained high through 2013. In nearby Mandaue, HIV remained below 4% through 2011 then rose rapidly to 38% by 2013.

Objectives: We hypothesize that infection prevalence differences in these cities may owe to aspects of social network structure, specifically levels of network clustering. Building on prior research, we hypothesize that higher levels of network clustering are associated with greater epidemic potential.

Methods: Data were collected with respondent-driven sampling among males who inject drugs in Cebu and Mandaue in 2013. We first examine sample composition using estimators for population means. We then apply new estimators of network clustering in respondent-driven sampling data to examine associations with HIV prevalence.

Results: Samples in both cities were comparable in terms of composition by age, education, and injection locations. Dyadic needle sharing levels were also similar between the two cities, but network clustering in the needle sharing network differed dramatically. We found higher clustering in Cebu than Mandaue, consistent with expectations that higher clustering is associated with faster epidemic spread.

Conclusion: This paper is the first to apply estimators of network clustering to empirical respondent-driven samples, and it offers suggestive evidence that researchers should pay greater attention to network structure's role in HIV transmission dynamics.

Abstract access

Africa, Asia
Malawi, Philippines, Uganda
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How are we going to get to our prevention targets? Old tools, new tools and a more nuanced understanding of transmission dynamics.

Editor’s notes: By 2020, the Fast-Track strategy is aiming to reduce new HIV infections to 200 000 per year.  There is increasing recognition that if we are to succeed, we will need to do much more than simply putting people onto HIV treatment.  Despite the massive impact of ART on infectiousness, the decline in new infections at the community level is still not fast enough, even in countries like Botswana (see above) where 90-90-90 has almost been reached.  Renewed enthusiasm for primary prevention has also followed key trials of biomedical prevention tools including voluntary medical male circumcision and ARV-based prevention.  It is all too easy for us to forget the crucial role that condoms have played from the early days of the epidemic.  More recently, with HIV seen as a less terrifying infection, many programmes suffer from “condom fatigue”.  So it is good to see papers on the key importance of condoms as well as perspectives on how they are perceived by young men.

The magic of ARVs does not end with treatment.  We are finally moving to wider use of pre-exposure prophylaxis (PrEP).  There is no doubt that PrEP works when taken, but there are still plenty of questions for policy-makers about how to adopt it whole-heartedly into their national strategic plans and for financiers about how to pay for it.  Papers this month cover a range of experiences with PrEP from the US, where the huge majority of PrEP users still live, to Europe and Australia, where policies are finally moving towards wider use.  Long acting PrEP remains a key objective for many, as it might improve regular adherence, which has proved the Achilles’ heel of oral and topical PrEP in several of the large studies.

One of the ways to make PrEP most cost-effective is to ensure that it is available to people who are most likely to acquire HIV.  So the hope continues that phylogenetic analyses will allow more sophisticated understanding of the dynamics of the multiple overlapping networks of HIV transmission in communities.  Papers this month cover Australia and the PANGEA consortium of African research sites along with a cautionary comment about establishing the ethical framework for such studies, particularly among populations who are already subject to discrimination and criminalization.

When used correctly and consistently, condoms are highly effective not only to prevent HIV but also to prevent pregnancy and to prevent sexually transmitted infections.  Stover and colleagues have tried to capture all three benefits in one model.  They explore three potential scenarios for condom programming between now and 2030 in 81 countries that are priorities for family planning or HIV programmers or both.  The benefits of greater investment in condoms are huge.  In their most optimistic scenario, the authors suggest that if the entire gap between people who would like to use condoms and people who currently use them was filled (almost 11 billion condoms over the period), this could prevent up to 400 million unwanted pregnancies; 16.8 million new HIV infections and more than 700 million sexually transmitted infections.  The costs are quite modest, and at $115 per DALY averted this is an investment that everyone should support.  There are of course limitations in such a broad brush model, but it provides an excellent starting point.

The challenges in provision of condoms to young people go well beyond the cost and effectiveness considerations that underpin the previous analysis.  In an interesting qualitative study in South Africa, de Bruin and Panday-Soobrayan report their findings from focus group discussions with learners in 33 public schools.  Most of the learners were not in favour of provision of condoms at school, although they were keen on more youth friendly sexual and reproductive health and rights services within the public sector.  Many thought that provision of condoms would lead to earlier and more frequent sexual contacts, despite considerable experience showing that this is not the case in other settings.

Multiple trials have shown that PrEP is extremely effective when it is used consistently and correctly.  Many countries in all continents are now beginning to work out where it fits within their combination prevention package.  To date, the large majority of PrEP users are in the United States of America (USA), where more than 140 000 people have started.  It is much harder to measure how many are still taking it regularly.  Patel and colleagues analysed utilization at three months after the initial prescription of PrEP in three major PrEP clinics in three states in the USA.  18% of the 201 people (90% male) seen at baseline did not use their PrEP and this was strongly predicted by insurance status, with around a four-fold risk of dropping out among those who were not insured.  Although the numbers are small, this is an important study.  The authors suggest that increased insurance cover might make PrEP have a greater impact.  More broadly it raises the challenge that PrEP is often needed most by people least able to access it.  This will be a real challenge in countries where people most at risk, such as gay men and other men who have sex with men and sex workers, are criminalized or discriminated against in many health care settings.

In Australia, PrEP has been provided through large demonstration projects while awaiting decisions about how to include it in routine practice.  Lal and colleagues report results from 114 (one transgender woman, the rest male) people taking PrEP in the Victorian PrEP Demonstration project.  Participants have to pay an equivalent of an insurance co-payment, in order to make the situation more like the “real world”.  The participants were recruited because they were at high risk of HIV engaging in condomless anal sex with partners who were known to be living with HIV or of unknown status.  Adherence to PrEP was excellent as measured by a variety of reported and biological measures.  They observed one seroconversion in a man with exposure two weeks before starting PrEP who was already in the process of seroconverting and whose virus was found to be resistant to emtricitabine.  The only other seroconversion occurred in someone who had not yet started PrEP.  The authors found a substantial increase in rates of gonorrhoea and chlamydia once participants were “stable” on PrEP after three months.  There was also a significant reduction in condom use with both regular and casual partners.  This is one of the first studies to document important risk compensation among PrEP users.  Of course, preventing HIV is a huge benefit that generally outweighs the harms of additional treatment for sexually transmitted infections.  However, the study emphasizes the importance of enhancing sexual health services alongside PrEP and reminds us that people most at risk of HIV are also at high risk of other infections (and also of pregnancy in the context of heterosexual transmission.)  If PrEP is integrated within a broad sexual health service, there could be considerable synergistic benefits.

Gay men and men who have sex with men who enrolled in the PrEP demonstration project in Amsterdam also had high concomitant rates of hepatitis C virus (HCV).  Hoorenborg and colleagues found that around 5% of the 375 men enrolled in the project were co-infected.  The HCV found among these men were genetically similar to those circulating in the population of gay men and other men who have sex with men living with HIV, and more distinct from HCV from other risk groups.  This is good evidence that HCV and HIV both circulate in this population, and emphasizes once again the need for more integrated services, including hepatitis screening.

The ÉCLAIR study is a phase 2a trial of cabotegravir injections in healthy HIV-negative male volunteers.  As noted, adherence is a major challenge in many PrEP trials; although notably less of a problem when people choose to take PrEP in demonstration projects.  It is hoped that cabotegravir could be the first long acting PrEP.  Markowitz and colleagues presented the results of this study at CROI 2017.  The authors point out that although the injections are painful, many men stated that they would be happy to continue if the injections were effective.  No serious safety challenges emerged. The pharmacokinetics suggests that a dose given more frequently will be needed – and subsequent trials will use a two monthly regimen. 

One group for whom PrEP has been recommended by WHO for some years are serodiscordant couples (SDCs).  The Partners PrEP study, which forms one of the cornerstones for the evidence that PrEP works for both men and women, was conducted in SDCs.  The idea is to protect the HIV-negative partner from infection until such time as the partner living with HIV has been on ART consistently and suppressed their viral load.  So a study from the Centers for Disease Control USA is relevant to discussions of PrEP.  Crepaz and colleagues found that around 6000 new HIV infections occur each year in the USA among men and women having heterosexual sex and are aware that their partner is living with HIV.  They point out that viral suppression is achieved by only around 50% of heterosexuals living with HIV and that an additional proportion does not know their HIV status.  So the importance of HIV testing, and of focusing efforts on serodiscordant couples is clear.  Such efforts include both improving HIV treatment effectiveness, and providing a range of prevention choices including PrEP until viral suppression is achieved.

While the study above used traditional epidemiological surveillance reports, phylogenetics may provide additional insights into the dynamics of transmission.  In Australia, where notifications with HIV are rising steadily,  Castley and colleagues have examined the sequence data from almost 5000 viruses collected across the country from 2005-2012.  This sample is drawn from around 1200 new HIV infections per year (and around 27 000 people living with HIV).  The sample is not random, but reflects samples that were sent for sequencing to determine drug resistance.  Around one quarter of sequences are found in tight clusters (pairs, triplets or more) with other sequences, making it likely that they are closely connected by transmission.  Of course, all HIV sequences have been transmitted, so a longer time period and complete sampling would be expected to give a much higher proportion in clusters.  Indeed the more recent samples are around twice as likely to be in clusters as those collected at the start of the time period. Nonetheless, the large sample and the time period of collection allows some clear observations to be made.  In all states, the proportion of non-B subtypes is increasing, which must relate to travel and migration to and from Asia and Africa.  There is little evidence that the C subtypes (originally from Africa) are found in all male clusters suggesting little spill over into the community of gay men and other men having sex with men.  Larger clusters are more common among younger, all male networks. Like most molecular epidemiological studies, there are a small number of large clusters which represent highly active transmission.  These clusters are also most likely to be all male.  Taken together, the results suggest that the steady rise in notifications in Australia is probably due to increasing migration and travel and to ongoing active transmission networks among young gay men.  The challenge is to turn this sort of analysis into clear policy recommendations that can improve HIV prevention.

UNAIDS joined an interesting meeting on the ethics of phylogenetic studies in Africa organised by the PANGEA consortium.  Many of the issues discussed are also covered in a comment by Cohen on the importance of thinking through the risks inherent in these studies.  A key issue is to ensure that systems are reinforced to monitor any unexpected harms and to establish mitigation strategies to minimize them.  The challenges are not necessarily different to traditional epidemiological studies which may highlight networks and locations of groups that are criminalized or discriminated against.  In community consultations, prior to agreeing to go forward with phylogenetic studies, some potential participants even say that they would be keen to “know who infected them” in order to punish them.  This is clearly NOT the aim of such studies and emphasizes the importance of clear information about the limitations of the techniques which cannot usually rule out the possibility of additional links in the transmission chain.  Issues of anonymised information and what to do if clinically relevant results such as drug resistance mutations are uncovered as incidental findings also need to be discussed.

Furthermore, Ratmann and colleagues, reporting on the first 4000 sequences from the PANGEA consortium (largely from the Rakai project in Uganda), also emphasize some of the technical challenges that may lead to erroneous results in creating phylogenies.  There is little doubt that as the cost of sequencing falls and as the technologies and software become increasingly straightforward, we will see more and more studies of sequence data.  It is likely that analysis of these data will lead to more nuanced approaches to HIV prevention, particularly as the overall incidence falls, and sharper tools are needed to dissect the pathways of ongoing transmission.

The case for investing in the male condom

Stover J, Rosen JE, Carvalho MN, Korenromp EL, Friedman HS, Cogan M, Deperthes B. PLoS One. 2017 May 16;12(5):e0177108. doi: 10.1371/journal.pone.0177108. eCollection 2017.

When used correctly and consistently, the male condom offers triple protection from unintended pregnancy and the transmission of sexually transmitted infections (STIs) and human immunodeficiency virus (HIV). However, with health funding levels stagnant or falling, it is important to understand the cost and health impact associated with prevention technologies. This study is one of the first to attempt to quantify the cost and combined health impact of condom use, as a means to prevent unwanted pregnancy and to prevent transmission of STIs including HIV. This paper describes the analysis to make the case for investment in the male condom, including the cost, impact and cost-effectiveness by three scenarios (low in which 2015 condom use levels are maintained; medium in which condom use trends are used to predict condom use from 2016-2030; and high in which condom use is scaled up, as part of a package of contraceptives, to meet all unmet need for family planning by 2030 and to 90% for HIV and STI prevention by 2016) for 81 countries from 2015-2030. An annual gap between current and desired use of 10.9 billion condoms was identified (4.6 billion for family planning and 6.3 billion for HIV and STIs). Under a high scenario that completely reduces that gap between current and desired use of 10.9 billion condoms, we found that by 2030 countries could avert 240 million DALYs. The additional cost in the 81 countries through 2030 under the medium scenario is $1.9 billion, and $27.5 billion under the high scenario. Through 2030, the cost-effectiveness ratios are $304 per DALY averted for the medium and $115 per DALY averted for the high scenario. Under the three scenarios described above, our analysis demonstrates the cost-effectiveness of the male condom in preventing unintended pregnancy and HIV and STI new infections. Policy makers should increase budgets for condom programming to increase the health return on investment of scarce resources.

Abstract  Full-text [free] access

Learners' perspectives on the provision of condoms in South African public schools.

de Bruin WE, Panday-Soobrayan S. AIDS care. 2017 May 16:1-4. doi: 10.1080/09540121.2017.1327647. [Epub ahead of print]

A stubborn health challenge for learners in South African public schools concerns sexual and reproductive health and rights (SRHR). In 2015, the Department of Basic Education (DBE) proposed the provision of condoms and SRHR-services to learners in schools. This study aimed to contribute to the finalisation and implementation of DBE's policy by exploring learners' perspectives on the provision of condoms and SRHR-services in schools. Sixteen focus group discussions were conducted with learners (n = 116) from 33 public schools, to assess their attitudes, social influences, and needs and desires regarding condom provision and SRHR-services in schools. The majority of learners did not support condom provision in schools as they feared that it may increase sexual activity. Contrarily, they supported the provision of other SRHR-services as clinics fail to offer youth-friendly services. Learners' sexual behaviour and access to SRHR-services are strongly determined by their social environment, including traditional norms and values, and social-pressure from peers and adults. Learners' most pressing needs and desires to access condoms and SRHR-services in school concerned respect, privacy and confidentiality of such service provision. Implementation of DBE's policy must be preceded by an evidence-informed advocacy campaign to debunk myths about the risk of increased sexual activity, to advocate for why such services are needed, to shift societal norms towards open discussion of adolescent SRHR and to grapple with the juxtaposition of being legally empowered but socially inhibited to protect oneself from HIV, STIs and early pregnancy. Provision of condoms and other SRHR-services in schools must be sensitive to learners' privacy and confidentiality to minimise stigma and discrimination.

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Impact of insurance coverage on utilization of pre-exposure prophylaxis for HIV prevention

Patel RR, Mena L, Nunn A, McBride T, Harrison LC, Oldenburg CE, Liu J, Mayer KH, Chan PA.  PLoS One. 2017 May 30;12(5):e0178737 . doi: 10.1371/journal.pone.0178737. eCollection 2017.

Pre-exposure prophylaxis (PrEP) can reduce U.S. HIV incidence. We assessed insurance coverage and its association with PrEP utilization. We reviewed patient data at three PrEP clinics (Jackson, Mississippi; St. Louis, Missouri; Providence, Rhode Island) from 2014-2015. The outcome, PrEP utilization, was defined as patient PrEP use at three months. Multivariable logistic regression was performed to determine the association between insurance coverage and PrEP utilization. Of 201 patients (Jackson: 34%; St. Louis: 28%; Providence: 28%), 91% were male, 51% were White, median age was 29 years, and 21% were uninsured; 82% of patients reported taking PrEP at three months. Insurance coverage was significantly associated with PrEP utilization. After adjusting for Medicaid-expansion and individual socio-demographics, insured patients were four times as likely to use PrEP services compared to the uninsured (OR: 4.49, 95% CI: 1.68-12.01; p = 0.003). Disparities in insurance coverage are important considerations in implementation programs and may impede PrEP utilization.

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Medication adherence, condom use and sexually transmitted infections in Australian PrEP users: interim results from the Victorian PrEP demonstration project

Lal L, Audsley J, Murphy D, Fairley CK, Stoove M, Roth N, Moore R, Tee BK, Puratmaja N, Anderson PL, Leslie D, Grant RM, De Wit J, Wright E; VicPrEP Study Team. AIDS. 2017 May 1 doi: 10.1097/QAD.0000000000001519. [Epub ahead of print]

Objective: HIV Pre-exposure prophylaxis (PrEP) decreases risk of HIV acquisition however its efficacy is closely dependent on adherence. There is also concern that the preventive effect of PrEP may be offset by risk compensation, notably an increase in condomless anal sex.

Design: Multi-site, open-label demonstration study that recruited people at current or recent risk of HIV infection in Melbourne, Australia.

Methods: Participants were recruited from three general practice clinics and one sexual health clinic in Melbourne and consented to take daily tenofovir/emtricitabine for 30 months. Sexual practice data, HIV and sexually transmitted infection (STI) test results were collected at baseline and 3-monthly during follow up. PrEP adherence was evaluated by self-report at clinical visits, online surveys, refill-based assessments and dried blood spot (DBS) testing. We present a 12-month interim analysis.

Results: 114 people were recruited. We observed a significant decline in condom use which occurred concomitantly with a significant increase in STIs over the first 12 months of PrEP. Incidence (per 100PY) of any STI was 43.2 and 119.8 at m0-3 and M3-12, respectively (IRR 2.77 (1.52, 5.56)). Adherence to PrEP medication was high by all measures, including six month TDF-FTC levels in DBS.

Conclusions: We found significant reduction in condom use and an increase STIs over the first 12 months of follow-up. High medication adherence rates coupled with a decline in condom use and a rise in STIs, suggests that prevention, early detection and treatment of STIs is a chief research priority in the current era of HIV PrEP.

Abstract

Men who have sex with men starting pre-exposure prophylaxis (PrEP) are at risk of HCV infection: evidence from the Amsterdam PrEP study

Hoornenborg E, Achterbergh RC, Van Der Loeff MF, Davidovich U, Hogewoning A, de Vries HJ, Schinkel J, Prins M, Laar TJWV; Amsterdam PrEP Project team in the HIV Transmission Elimination AMsterdam Initiative, MOSAIC study group. AIDS. 2017 May 1. doi: 10.1097/QAD.0000000000001522. [Epub ahead of print].

Objectives and Design: Hepatitis C virus (HCV) has been recognised as an emerging sexually transmitted infection (STI) among HIV-positive men who have sex with men (MSM). However, HIV-negative MSM at high risk for HIV might also be at increased risk for HCV. We studied the HCV prevalence in HIV-negative MSM who start pre-exposure prophylaxis (PrEP) in Amsterdam. Phylogenetic analysis was used to compare HCV strains obtained from HIV-negative and HIV-positive MSM.

Methods: At enrolment in the Amsterdam PrEP (AMPrEP) demonstration project, HIV-negative MSM were tested for the presence of HCV antibodies and HCV RNA. If positive for HCV RNA, an HCV NS5B gene fragment (709 bp) was sequenced and compared with HCV isolates from HIV-positive MSM (n = 223) and risk groups other than MSM (n = 153), using phylogenetic analysis.

Results: Of 375 HIV-negative MSM enrolled in AMPrEP, 18 (4.8%, 95%CI 2.9%-7.5%) of participants were anti-HCV and/or HCV RNA positive at enrolment; 15/18 (83%) had detectable HCV RNA. HCV genotyping showed genotype 1a (73%), 4d (20%) and 2b (7%). All HCV-positive MSM starting PrEP were part of MSM-specific HCV clusters containing MSM with and without HIV.

Conclusion: HCV prevalence among HIV-negative MSM who started PrEP was higher than previously reported. All HIV-negative HCV-positive MSM were infected with HCV strains already circulating among HIV-positive MSM. The increasing overlap between sexual networks of HIV-positive and HIV-negative MSM might result in an expanding HCV-epidemic irrespective of HIV-status. Hence, routine HCV testing should be offered to MSM at high risk for HIV, especially for those enrolling in PrEP programs.

Abstract

Safety and tolerability of long-acting cabotegravir injections in HIV-uninfected men (ECLAIR): a multicentre, double-blind, randomised, placebo-controlled, phase 2a trial.

Markowitz M, Frank I, Grant RM, Mayer KH, Elion R, Goldstein D, Fisher C, Sobieszczyk ME, Gallant JE, Van Tieu H, Weinberg W, . Margolis DA, Hudson KJ, Stancil BS, Ford SL, Patel P, Gould E, Rinehart AR, Smith KY, Spreen WR. Lancet HIV. 2017 May 22. pii: S2352-3018(17)30068-1. doi: 10.1016/S2352-3018(17)30068-1. [Epub ahead of print]

Background: Cabotegravir (GSK1265744) is an HIV-1 integrase strand transfer inhibitor with potent antiviral activity and a long half-life when administered by injection that prevented simian-HIV infection upon repeat intrarectal challenge in male macaques. We aimed to assess the safety, tolerability, and pharmacokinetics of long-acting cabotegravir injections in healthy men not at high risk of HIV-1 infection.

Methods: We did this multicentre, double-blind, randomised, placebo-controlled, phase 2a trial at ten sites in the USA. Healthy men (aged 18-65 years) deemed not at high risk of acquiring HIV-1 at screening were randomly assigned (5:1), via computer-generated central randomisation schedules, to receive cabotegravir or placebo. Participants received oral cabotegravir 30 mg tablets or matching placebo once daily during a 4 week oral lead-in phase, followed by a 1 week washout period and, after safety assessment, three intramuscular injections of long-acting cabotegravir 800 mg or saline placebo at 12 week intervals. Study site staff and participants were masked to treatment assignment from enrolment through week 41 (time of the last injection). The primary endpoint was safety and tolerability from the first injection (week 5) to 12 weeks after the last injection. We did analysis in the safety population, defined as all individuals enrolled in the study who received at least one dose of the study drug. This study is registered with ClinicalTrials.gov identifier, NCT02076178.

Findings: Between March 27, 2014, and Feb 23, 2016, we randomly assigned 127 participants to receive cabotegravir (n=106) or placebo (n=21); 126 (99%) participants comprised the safety population. Most participants were men who have sex with men (MSM; n=106 [83%]) and white (n=71 [56%]). 87 (82%) participants in the cabotegravir group and 20 (95%) participants in the placebo group completed the injection phase. Adverse events (n=7 [7%]) and injection intolerability (n=4 [4%]) were the main reasons for withdrawal in the cabotegravir group. The frequency of grade 2 or higher adverse events was higher in participants in the long-acting cabotegravir group (n=75 [80%]) than in those in the placebo group (n=10 [48%]; p=0·0049), mostly due to injection-site pain (n=55 [59%]). No significant differences were noted in concomitant medications, laboratory abnormalities, electrocardiogram, and vital sign assessments. Geometric mean trough plasma concentrations were 0·302 μg/mL (95% CI 0·237-0·385), 0·331 μg/mL (0·253-0·435), and 0·387 μg/mL (0·296-0·505) for injections one, two, and three, respectively, indicating lower than predicted exposure. The geometric mean apparent terminal phase half-life estimated after the third injection was 40 days. Two (2%) MSM acquired HIV-1 infection, one in the placebo group during the injection phase and one in the cabotegravir group 24 weeks after the final injection when cabotegravir exposure was well below the protein-binding-adjusted 90% inhibitory concentration.

Interpretation: Despite high incidence of transient, mild-to-moderate injection-site reactions, long-acting cabotegravir was well tolerated with an acceptable safety profile. Pharmacokinetic data suggest that 800 mg administered every 12 weeks is a suboptimal regimen; alternative dosing strategies are being investigated. Our findings support further investigation of long-acting injectable cabotegravir as an alternative to orally administered pre-exposure prophylaxis regimens.

Abstract

Examination of HIV infection through heterosexual contact with partners who are known to be HIV infected in the United States, 2010-2015

Crepaz N, Dong B, Chen M, Hall I. AIDS. 2017 Jul 17;31(11):1641-1644. doi: 10.1097/QAD.0000000000001526.

Using data from the National HIV Surveillance System, we examined HIV infections diagnosed between 2010 and 2015 attributed to heterosexual contact with partners previously known to be HIV infected. More than four in 10 HIV infections among heterosexual males and five in 10 HIV infections among heterosexual women were attributed to this group. Findings may inform the prioritization of prevention and care efforts and resource allocation modeling for reducing new HIV infection among discordant partnerships.

Abstract

A national study of the molecular epidemiology of HIV-1 in Australia 2005–2012

Castley A, Sawleshwarkar S, Varma R, Herring B, Thapa K, Dwyer D, Chibo D, Nguyen N, Hawke K, Ratcliff R, Garsia R, Kelleher A, Nolan D; Australian Molecular Epidemiology Network-HIV (AMEN-HIV).. PLoS One. 2017 May 10;12(5):e0170601. doi: 10.1371/journal.pone.0170601. eCollection 2017.

Introduction: Rates of new HIV-1 diagnoses are increasing in Australia, with evidence of an increasing proportion of non-B HIV-1 subtypes reflecting a growing impact of migration and travel. The present study aims to define HIV-1 subtype diversity patterns and investigate possible HIV-1 transmission networks within Australia.

Methods: The Australian Molecular Epidemiology Network (AMEN) HIV collaborating sites in Western Australia, South Australia, Victoria, Queensland and western Sydney (New South Wales), provided baseline HIV-1 partial pol sequence, age and gender information for 4873 patients who had genotypes performed during 2005-2012. HIV-1 phylogenetic analyses utilised MEGA V6, with a stringent classification of transmission pairs or clusters (bootstrap ≥98%, genetic distance ≤1.5% from at least one other sequence in the cluster).

Results: HIV-1 subtype B represented 74.5% of the 4873 sequences (WA 59%, SA 68.4%, w-Syd 73.8%, Vic 75.6%, Qld 82.1%), with similar proportion of transmission pairs and clusters found in the B and non-B cohorts (23% vs 24.5% of sequences, p = 0.3). Significantly more subtype B clusters were comprised of ≥3 sequences compared with non-B clusters (45.0% vs 24.0%, p = 0.021) and significantly more subtype B pairs and clusters were male-only (88% compared to 53% CRF01_AE and 17% subtype C clusters). Factors associated with being in a cluster of any size included; being sequenced in a more recent time period (p<0.001), being younger (p<0.001), being male (p = 0.023) and having a B subtype (p = 0.02). Being in a larger cluster (>3) was associated with being sequenced in a more recent time period (p = 0.05) and being male (p = 0.008).

Conclusion: This nationwide HIV-1 study of 4873 patient sequences highlights the increased diversity of HIV-1 subtypes within the Australian epidemic, as well as differences in transmission networks associated with these HIV-1 subtypes. These findings provide epidemiological insights not readily available using standard surveillance methods and can inform the development of effective public health strategies in the current paradigm of HIV prevention in Australia

Abstract  Full-text [free] access

HIV-1 full-genome phylogenetics of generalized epidemics in sub-Saharan Africa: impact of missing nucleotide characters in next-generation sequences.

Ratmann O, Wymant C, Colijn C, Danaviah S, Essex M, Frost SD, Gall A, Gaiseitsiwe S, Grabowski M, Gray R, Guindon S, von Haeseler A, Kaleebu P, Kendall M, Kozlov A, Manasa J, Minh BQ, Moyo S, Novitsky V, Nsubuga R, Pillay S, Quinn TC, Serwadda D, Ssemwanga D, Stamatakis A, Trifinopoulos J, Wawer M, Leigh Brown A, de Oliveira T, Kellam P, Pillay D, Fraser C.. AIDS Res Hum Retroviruses. 2017 May 25. doi: 10.1089/AID.2017.0061. [Epub ahead of print].

To characterize HIV-1 transmission dynamics in regions where the burden of HIV-1 is greatest, the 'Phylogenetics and Networks for Generalised HIV Epidemics in Africa' consortium (PANGEA-HIV) is sequencing full-genome viral isolates from across sub-Saharan Africa. We report the first 3985 PANGEA-HIV consensus sequences from four cohort sites (Rakai Community Cohort Study, n=2833; MRC/UVRI Uganda, n=701; Mochudi Prevention Project, n=359; Africa Health Research Institute Resistance Cohort, n=92). Next-generation sequencing success rates varied: more than 80% of the viral genome from the gag to the nef genes could be determined for all sequences from South Africa, 75% of sequences from Mochudi, 60% of sequences from MRC/UVRI Uganda, and 22% of sequences from Rakai. Partial sequencing failure was primarily associated with low viral load, increased for amplicons closer to the 3' end of the genome, was not associated with subtype diversity except HIV-1 subtype D, and remained significantly associated with sampling location after controlling for other factors. We assessed the impact of the missing data patterns in PANGEA-HIV sequences on phylogeny reconstruction in simulations. We found a threshold in terms of taxon sampling below which the patchy distribution of missing characters in next-generation sequences has an excess negative impact on the accuracy of HIV-1 phylogeny reconstruction, which is attributable to tree reconstruction artifacts that accumulate when branches in viral trees are long. The large number of PANGEA-HIV sequences provides unprecedented opportunities for evaluating HIV-1 transmission dynamics across sub-Saharan Africa and identifying prevention opportunities. Molecular epidemiological analyses of these data must proceed cautiously because sequence sampling remains below the identified threshold and a considerable negative impact of missing characters on phylogeny reconstruction is expected.

Abstract  Full-text [free] access

 

Africa, Asia, Europe, Northern America, Oceania
Afghanistan, Angola, Australia, Azerbaijan, Bangladesh, Benin, Bolivia, Botswana, Brazil, Burkina Faso, Burundi, Cambodia, Cameroon, Central African Republic, Chad, China, Comoros, Congo, Côte d'Ivoire, Democratic People's Republic of Korea, Democratic Republic of the Congo, Djibouti, Egypt, Equatorial Guinea, Eritrea, Ethiopia, Gabon, Gambia, Ghana, Guatemala, Guinea, Guinea-Bissau, Haiti, India, Indonesia, Iran (Islamic Republic of), Iraq, Jamaica, Kenya, Kyrgyzstan, Lao People's Democratic Republic, Lesotho, Liberia, Madagascar, Malawi, Mauritania, Mexico, Morocco, Mozambique, Myanmar, Namibia, Nepal, Netherlands, Niger, Nigeria, Pakistan, Papua New Guinea, Peru, Philippines, Russian Federation, Rwanda, Sao Tome and Principe, Senegal, Sierra Leone, Solomon Islands, Somalia, South Africa, South Sudan, Sudan, Swaziland, Tajikistan, Togo, Turkmenistan, Uganda, Ukraine, United Republic of Tanzania, United States of America, Uzbekistan, Viet Nam, Yemen, Zambia, Zimbabwe
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Demand-side activities are essential for achieving population level impact of HIV prevention tools

Interventions to strengthen the HIV prevention cascade: a systematic review of reviews.

Krishnaratne S, Hensen B, Cordes J, Enstone J, Hargreaves JR. Lancet HIV. 2016 Jul;3(7):e307-17. doi: 10.1016/S2352-3018(16)30038-8.

Background: Much progress has been made in interventions to prevent HIV infection. However, development of evidence-informed prevention programmes that translate the efficacy of these strategies into population effect remain a challenge. In this systematic review, we map current evidence for HIV prevention against a new classification system, the HIV prevention cascade.

Methods: We searched for systematic reviews on the effectiveness of HIV prevention interventions published in English from Jan 1, 1995, to July, 2015. From eligible reviews, we identified primary studies that assessed at least one of: HIV incidence, HIV prevalence, condom use, and uptake of HIV testing. We categorised interventions as those seeking to increase demand for HIV prevention, improve supply of HIV prevention methods, support adherence to prevention behaviours, or directly prevent HIV. For each specific intervention, we assigned a rating based on the number of randomised trials and the strength of evidence.

Findings: From 88 eligible reviews, we identified 1964 primary studies, of which 292 were eligible for inclusion. Primary studies of direct prevention mechanisms showed strong evidence for the efficacy of pre-exposure prophylaxis (PrEP) and voluntary medical male circumcision. Evidence suggests that interventions to increase supply of prevention methods such as condoms or clean needles can be effective. Evidence arising from demand-side interventions and interventions to promote use of or adherence to prevention tools was less clear, with some strategies likely to be effective and others showing no effect. The quality of the evidence varied across categories.

Interpretation: There is growing evidence to support a number of efficacious HIV prevention behaviours, products, and procedures. Translating this evidence into population impact will require interventions that strengthen demand for HIV prevention, supply of HIV prevention technologies, and use of and adherence to HIV prevention methods.

Abstract  Full-text [free] access

Editor’s notes: Demand, supply and use of programmes are crucial for the uptake and effective use of HIV prevention strategies. This paper presents an impressive undertaking in which the authors conducted a review of systematic reviews on the evidence for the effectiveness of HIV prevention programmes across the multiple steps in an HIV prevention cascade. This particular prevention cascade allocates programmes into demand-side, supply-side, adherence, and direct HIV prevention technologies. This was published in a separate paper in conjunction with this review. The review found that there is strong evidence with regards to which direct HIV prevention technologies are efficacious, as well as maps where adherence and supply-side programmes have been effective. A primary gap was noted on the demand-side of the cascade (e.g. information, education and communication, and peer-based activities to increase demand for medical male circumcision) where studies have not resulted in reducing HIV incidence or prevalence. There remains a need to understand why, despite supply, there is low uptake of some HIV prevention strategies, and for evaluation of novel activities to increase demand.  

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Profound effect of ART on mortality through reduction of opportunistic infections

Incidence of opportunistic infections and the impact of antiretroviral therapy among HIV-infected adults in low and middle income countries: a systematic review and meta-analysis. 

Low A, Gavriilidis G, Larke N, Lajoie MR, Drouin O, Stover J, Muhe L, Easterbrook P. Clin Infect Dis. 2016 Mar 6. pii: ciw125. [Epub ahead of print]

Background: To understand regional burdens and inform delivery of health services, we conducted a systematic review and meta-analysis to evaluate the effect of antiretroviral therapy (ART) on incidence of key opportunistic infections (OIs) in HIV-infected adults in low and middle-income countries (LMIC).

Methods: Eligible studies describing the cumulative incidence of OIs and proportion on ART from 1990 to November 2013 were identified using multiple databases. Summary incident risks for the ART-naive period, and during and after the first year of ART, were calculated using random effects meta-analyses. Summary estimates from ART subgroups were compared using meta-regression. The number of OI cases and associated costs averted if ART was initiated at CD4 ≥200 cells/µl was estimated using UNAIDS country estimates and global average OI treatment cost per case.

Results: We identified 7965 citations, and included 126 studies describing 491 608 HIV-infected persons. In ART-naive patients, summary risk was highest (>5%) for oral candidiasis, tuberculosis, herpes zoster, and bacterial pneumonia. The reduction in incidence was greatest for all OIs during the first 12 months of ART (range 57-91%) except for tuberculosis, and was largest for oral candidiasis, PCP and toxoplasmosis. Earlier ART was estimated to have averted 857 828 cases in 2013 (95% confidence interval [CI], 828 032-874 853), with cost savings of $46.7 million (95% CI, 43.8-49.4).

Conclusions: There was a major reduction in risk for most OIs with ART use in LMICs, with the greatest effect seen in the first year of treatment. ART has resulted in substantial cost savings from OIs averted.

Abstract  Full-text [free] access

Editor’s notes: Opportunistic infections (OIs) remain the major cause of HIV-associated mortality. OIs account for substantially higher mortality in low and middle income countries (LMICs) compared to high income countries (HICs).

This paper describes the results of a systematic review and meta-analysis including about 500 000 people on ART in LMICs across three regions (sub-Saharan Africa, Asia, and Latin America). These large numbers enabled the investigators to look at the effect of ART on the incidence of key OIs during and after the first year of treatment.

Not surprisingly they found that the effect of ART reduced the risk of all OIs during the first year after ART initiation, although the reduction was less for tuberculosis. The authors attribute this to the occurrence of tuberculosis across a wide range of CD4 cell counts, a smaller effect of early immune restoration and the contribution of TB as a manifestation of immune reconstitution syndrome during the first months after ART initiation. Beyond one year after ART initiation, the reduction in tuberculosis was greater.

They conclude that the effect of ART on the incidence of most HIV-associated OIs is the key reason for the global decline in HIV-associated mortality. However, a significant proportion of HIV-positive persons still continue to present with advanced disease. Besides timely ART initiation, additional measures such as CTX prophylaxis, screening for TB and cryptococcal disease, and the use of isoniazid and fluconazole prophylaxis should be considered for late presenters. 

Africa, Asia, Latin America
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The effects of trauma follow people on the move

A systematic review of HIV risk behaviors and trauma among forced and unforced migrant populations from low and middle-income countries: state of the literature and future directions.

Michalopoulos LM, Aifah A, El-Bassel N. AIDS Behav. 2016 Feb;20(2):243-61. doi: 10.1007/s10461-015-1014-1.

The aim of the current systematic review is to examine the relationship between trauma and HIV risk behaviors among both forced and unforced migrant populations from low and middle income countries (LMIC). We conducted a review of studies published from 1995 to 2014. Data were extracted related to (1) the relationship between trauma and HIV risk behaviors, (2) methodological approach, (3) assessment methods, and (4) differences noted between forced and unforced migrants. A total of 340 records were retrieved with 24 studies meeting inclusion criteria. Our review demonstrated an overall relationship between trauma and HIV risk behaviors among migrant populations in LMIC, specifically with sexual violence and sexual risk behavior. However, findings from 10 studies were not in full support of the relationship. Findings from the review suggest that additional research using more rigorous methods is critically needed to understand the nature of the relationship experienced by this key-affected population.

Abstract access

Editor’s notes: The number of forced and unforced migrants is growing globally. Refugees, asylum seekers, and internally displaced persons (IDP) are forced migrants who often migrate due to political violence or conflict. Labour migrants are seen as unforced migrants who choose to emigrate for economic reasons. About half of labour migrants worldwide are women who are increasingly migrating on their own being the sole income provider for their families. With respect to trauma exposure and HIV risk in settings of long-term political violence and conflict, the distinction between war migrant, non-war migrant, and long-term resident is blurred. This in-depth review of 24 studies related to low-and middle-income countries (LMIC), mostly from sub-Saharan Africa, found findings similar to those from non-migrant populations in high-income countries. These linked traumatic experiences among migrant populations with HIV risk behaviours. Sexual violence was consistently associated with HIV sexual risk behaviours and HIV infection across the studies. But there are big gaps in the scientific literature. For example, the relationship between trauma and HIV risks has been explored for female labour migrants who are sex workers but not among women who have other occupations. Most studies addressed sexual risk and alcohol dependence, but injecting drug risk behaviours and use of any illicit drugs were virtually ignored by most studies. Few studies examined a possible link for trauma that occurred pre-migration and post-migration. Three qualitative studies examined male migrants who have sex with men, finding that violent experiences and discrimination and stigma associated with homophobia, combined with other migrant-associated traumas, can compound their mental health outcomes and subsequent HIV risk behaviours – but all were only conducted in the last four years. No studies were found that focused on HIV prevention programmes to address trauma and HIV risks among migrant workers in LMIC. However, the studies do reveal important factors that prevention programmes would have to consider. For example, concerns among labour migrants about dangerous working conditions may take precedence over HIV risk perceptions and the need for safer sex. This systematic review presents a wealth of information while highlighting the need to improve the quality of scientific research examining the link between HIV and trauma among both forced and unforced migrants in LMIC. 

Africa, Asia, Europe, Latin America
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Expanding ART access: increasing costs

The HIV treatment gap: estimates of the financial resources needed versus available for scale-up of antiretroviral therapy in 97 countries from 2015 to 2020.

Dutta A, Barker C, Kallarakal A. PLoS Med. 2015 Nov 24;12(11):e1001907. doi: 10.1371/journal.pmed.1001907. eCollection 2015.

Background: The World Health Organization (WHO) released revised guidelines in 2015 recommending that all people living with HIV, regardless of CD4 count, initiate antiretroviral therapy (ART) upon diagnosis. However, few studies have projected the global resources needed for rapid scale-up of ART. Under the Health Policy Project, we conducted modeling analyses for 97 countries to estimate eligibility for and numbers on ART from 2015 to 2020, along with the facility-level financial resources required. We compared the estimated financial requirements to estimated funding available.

Methods and findings: Current coverage levels and future need for treatment were based on country-specific epidemiological and demographic data. Simulated annual numbers of individuals on treatment were derived from three scenarios: (1) continuation of countries' current policies of eligibility for ART, (2) universal adoption of aspects of the WHO 2013 eligibility guidelines, and (3) expanded eligibility as per the WHO 2015 guidelines and meeting the Joint United Nations Programme on HIV/AIDS "90-90-90" ART targets. We modeled uncertainty in the annual resource requirements for antiretroviral drugs, laboratory tests, and facility-level personnel and overhead.

We estimate that 25.7 (95% CI 25.5, 26.0) million adults and 1.57 (95% CI 1.55, 1.60) million children could receive ART by 2020 if countries maintain current eligibility plans and increase coverage based on historical rates, which may be ambitious. If countries uniformly adopt aspects of the WHO 2013 guidelines, 26.5 (95% CI 26.0 27.0) million adults and 1.53 (95% CI 1.52, 1.55) million children could be on ART by 2020. Under the 90-90-90 scenario, 30.4 (95% CI 30.1, 30.7) million adults and 1.68 (95% CI 1.63, 1.73) million children could receive treatment by 2020. The facility-level financial resources needed for scaling up ART in these countries from 2015 to 2020 are estimated to be US$45.8 (95% CI 45.4, 46.2) billion under the current scenario, US$48.7 (95% CI 47.8, 49.6) billion under the WHO 2013 scenario, and US$52.5 (95% CI 51.4, 53.6) billion under the 90-90-90 scenario. After projecting recent external and domestic funding trends, the estimated 6-y financing gap ranges from US$19.8 billion to US$25.0 billion, depending on the costing scenario and the U.S. President's Emergency Plan for AIDS Relief contribution level, with the gap for ART commodities alone ranging from US$14.0 to US$16.8 billion. The study is limited by excluding above-facility and other costs essential to ART service delivery and by the availability and quality of country- and region-specific data.

Conclusions: The projected number of people receiving ART across three scenarios suggests that countries are unlikely to meet the 90-90-90 treatment target (81% of people living with HIV on ART by 2020) unless they adopt a test-and-offer approach and increase ART coverage. Our results suggest that future resource needs for ART scale-up are smaller than stated elsewhere but still significantly threaten the sustainability of the global HIV response without additional resource mobilization from domestic or innovative financing sources or efficiency gains. As the world moves towards adopting the WHO 2015 guidelines, advances in technology, including the introduction of lower-cost, highly effective antiretroviral regimens, whose value are assessed here, may prove to be "game changers" that allow more people to be on ART with the resources available.

Abstract Full-text [free] access

Editor’s notes: This is a complex and important paper that seeks to understand the financial requirements necessary to: a) continue countries’ current policies of eligibility for ART, b) roll out universal adoption of certain aspects of WHO 2013 eligibility guidelines, and c) expand eligibility as per WHO 2015 guidelines and meeting the Joint United Nations Programme on HIV/AIDS ‘90-90-90’ targets.

The authors estimated the number of adults and children eligible for and receiving HIV treatment, as well as the cost of providing ART in 97 countries across six regions, covering different income levels. They estimated that 25.7 million adults and 1.57 million children could receive ART by 2020 if countries maintain the current eligibility strategies. If countries adopted WHO 2013 eligibility guidelines, 26.5 million adults and 1.53 million children would be on ART by 2020, and if they adopted the 90-90-90 scenario, 30.4 million adults and 1.68 million children could receive treatment by then. The financial resources necessary for this scale up are estimated to be US$ 45.8 billion under current eligibility, US$ 48.7 billion under WHO 2013 scenario and US$ 52.5 billion under the 90-90-90 scenario. The estimated funding gap for the six year period ranges between US$ 20 and US$ 25 billion. In this study, the costs of commodities were taken directly from data collated by other organisations.  No empirical cost estimates of service delivery were made.  Nor was there an attempt to understand the cost implications of the development synergies and social and programme enablers that may be needed to increase the number of people living with HIV knowing their status.  The new WHO recommendations need to be actively pursued if we are to meet targets, rather than passively continuing with “business as usual”. 

Nonetheless, the findings of this study highlight the gap between guidelines written by WHO and very real programmatic obstacles on the ground. There is evidence to suggest that universal test-and-treat strategies could lead to substantially improved health outcomes at the population level, as well as potentially being cost-saving in the long-term. However, as the authors have illustrated, it would require increased levels of funding. What needs to be explored further now is how to overcome the logistical hurdles of rolling out such an initiative. Changing systems and practices is costly and takes time. Health workers will have to be retrained, data collection strategies will have to be revised. Expanding treatment may also mean increasing the number of health staff working on this initiative, which has an opportunity cost that may reverberate in other parts of the health system. Substantially altering health service provision, particularly in weak health systems, may have knock-on effects with unexpected and unintended consequences.

WHO guidelines serve a vital purpose of giving us a goal to aim for. But studies like this one help us know if and how we can get there. 

Africa, Asia, Europe, Latin America, Oceania
Algeria, Angola, Armenia, Azerbaijan, Bahamas, Bangladesh, Barbados, Belarus, Belize, Benin, Bhutan, Bolivia, Botswana, Bulgaria, Burkina Faso, Burundi, Cambodia, Cameroon, Central African Republic, Chad, China, Comoros, Côte d'Ivoire, Cuba, Democratic Republic of the Congo, Djibouti, Dominican Republic, Egypt, Equatorial Guinea, Eritrea, Ethiopia, Gabon, Gambia, Georgia, Ghana, Guatemala, Guinea, Guinea-Bissau, Guyana, Haiti, Honduras, India, Indonesia, Iran (Islamic Republic of), Jamaica, Kazakhstan, Kenya, Kyrgyzstan, Lao People's Democratic Republic, Lesotho, Liberia, Madagascar, Malawi, Malaysia, Mali, Mauritania, Mauritius, Moldova, Mongolia, Morocco, Mozambique, Myanmar, Namibia, Nepal, Nicaragua, Niger, Nigeria, Pakistan, Papua New Guinea, Philippines, Republic of the Congo, Romania, Russia, Rwanda, Senegal, Serbia and Montenegro, Sierra Leone, Somalia, South Africa, Sri Lanka, Sudan, Suriname, Swaziland, Tajikistan, Thailand, Togo, Trinidad and Tobago, Tunisia, Uganda, Ukraine, United Republic of Tanzania, Uzbekistan, Viet Nam, Yemen, Zambia, Zimbabwe
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Increasing transmitted resistance to antiretroviral therapy in low/middle-income countries - highest prevalence in MSM

Global burden of transmitted HIV drug resistance and HIV-exposure categories: a systematic review and meta-analysis.

Pham QD, Wilson DP, Law MG, Kelleher AD, Zhang L. AIDS. 2014 Nov 28;28(18):2751-62. doi: 10.1097/QAD.0000000000000494.

Objectives: Our aim was to review the global disparities of transmitted HIV drug resistance (TDR) in antiretroviral-naive MSM, people who inject drugs (PWID) and heterosexual populations in both high-income and low/middle-income countries.

Design/methods: We undertook a systematic review of the peer-reviewed English literature on TDR (1999-2013). Random-effects meta-analyses were performed to pool TDR prevalence and compare the odds of TDR across at-risk groups.

Results: A total of 212 studies were included in this review. Areas with greatest TDR prevalence were North America (MSM: 13.7%, PWID: 9.1%, heterosexuals: 10.5%); followed by western Europe (MSM: 11.0%, PWID: 5.7%, heterosexuals: 6.9%) and South America (MSM: 8.3%, PWID: 13.5%, heterosexuals: 7.5%). Our data indicated disproportionately high TDR burdens in MSM in Oceania (Australia 15.5%), eastern Europe/central Asia (10.2%) and east Asia (7.8%). TDR epidemics have stabilized in high-income countries, with a higher prevalence (range 10.9-12.6%) in MSM than in PWID (5.2-8.3%) and heterosexuals (6.4-9.0%) over 1999-2013. In low/middle-income countries, TDR prevalence in all at-risk groups in 2009-2013 almost doubled than that in 2004-2008 (MSM: 7.8 vs. 4.2%, P = 0.011; heterosexuals: 4.1 vs. 2.6%, P < 0.001; PWID: 4.8 vs. 2.4%, P = 0.265, respectively). The risk of TDR infection was significantly greater in MSM than that in heterosexuals and PWID. We observed increasing trends of resistance to non-nucleoside reverse transcriptase and protease inhibitors among MSM.

Conclusion: TDR prevalence is stabilizing in high-income countries, but increasing in low/middle-income countries. This is likely due to the low, but increasing, coverage of antiretroviral therapy in these settings. Transmission of TDR is most prevalent among MSM worldwide.

Abstract access 

Editor’s notes: HIV mutates very rapidly, and many early antiretroviral agents had a low genetic barrier to the development of resistance. Thus the emergence of virus resistant to antiretroviral agents, particularly to early drug classes, was inevitable. Surveillance for drug-resistant virus among people with no prior history of taking antiretroviral drugs (transmitted drug resistance) is essential to monitor the spread of drug resistance at population level.

This systematic review aimed to compare transmitted drug resistance in different geographical regions and between subpopulations of HIV-positive people by likely route of transmission. Transmitted resistance was most prevalent in high income settings. This is not surprising given wide use of suboptimal drug regimens before effective triple therapy was available. Reassuringly, the prevalence of transmitted resistance seems to have stabilised in high-income settings. The increase in transmitted resistance in low and middle income countries is of more concern. It is not surprising, given that first-line regimens comprising two nucleoside reverse transcriptase inhibitors and a non-nucleoside reverse transcriptase inhibitor are vulnerable to the development of resistance if the drug supply is interrupted or adherence is suboptimal. In addition, if viral load monitoring is not available, people remain on failing drug regimens for longer, and thus have more risk of transmitting resistant virus.

Within the subpopulations examined in this review, transmitted resistance was consistently higher in men who have sex with men, suggesting that resistance testing prior to treatment is particularly valuable for this population.

Limitations of the review include exclusion of studies that did not compare transmitted resistance between the specified subpopulations, and small sample size in many subgroups.

Continued surveillance for transmitted drug resistance is critical. This is most important in settings where individualised resistance testing is not available. This will ensure that people starting antiretroviral therapy receive treatment that will suppress their viral load effectively. Wider use of viral load monitoring, combined with access to effective second and third line regimens, will also help limit spread of drug resistance.

HIV Treatment
Angola, Argentina, Australia, Austria, Belgium, Benin, Botswana, Brazil, Burkina Faso, Cambodia, Cameroon, Canada, Central African Republic, Chad, China, Côte d'Ivoire, Croatia, Cuba, Cyprus, Denmark, Dominican Republic, El Salvador, Estonia, Ethiopia, France, Gabon, Georgia, Germany, Greece, Guatemala, Honduras, Hong Kong Special Administrative Region of China, Hungary, India, Indonesia, Ireland, Israel, Italy, Japan, Kazakhstan, Kenya, Latvia, Malawi, Malaysia, Moldova, Mozambique, Netherlands, Peru, Philippines, Poland, Portugal, Republic of Korea, Romania, Russia, Rwanda, Slovenia, South Africa, Spain, Swaziland, Sweden, Switzerland, Taiwan, Thailand, Uganda, United Kingdom of Great Britain and Northern Ireland, United Republic of Tanzania, United States of America, Viet Nam, Zambia, Zimbabwe
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Counting and classifying global deaths

Global, regional, and national incidence and mortality for HIV, tuberculosis, and malaria during 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013.

Murray CJ, Ortblad KF, Guinovart C, et al. Lancet. 2014 Sep 13;384(9947):1005-70. doi: 10.1016/S0140-6736(14)60844-8. Epub 2014 Jul 22.

Background: The Millennium Declaration in 2000 brought special global attention to HIV, tuberculosis, and malaria through the formulation of Millennium Development Goal (MDG) 6. The Global Burden of Disease 2013 study provides a consistent and comprehensive approach to disease estimation for between 1990 and 2013, and an opportunity to assess whether accelerated progress has occurred since the Millennium Declaration.

Methods: To estimate incidence and mortality for HIV, we used the UNAIDS Spectrum model appropriately modified based on a systematic review of available studies of mortality with and without antiretroviral therapy (ART). For concentrated epidemics, we calibrated Spectrum models to fit vital registration data corrected for misclassification of HIV deaths. In generalised epidemics, we minimised a loss function to select epidemic curves most consistent with prevalence data and demographic data for all-cause mortality. We analysed counterfactual scenarios for HIV to assess years of life saved through prevention of mother-to-child transmission (PMTCT) and ART. For tuberculosis, we analysed vital registration and verbal autopsy data to estimate mortality using cause of death ensemble modelling. We analysed data for corrected case-notifications, expert opinions on the case-detection rate, prevalence surveys, and estimated cause-specific mortality using Bayesian meta-regression to generate consistent trends in all parameters. We analysed malaria mortality and incidence using an updated cause of death database, a systematic analysis of verbal autopsy validation studies for malaria, and recent studies (2010-13) of incidence, drug resistance, and coverage of insecticide-treated bednets.

Findings: Globally in 2013, there were 1.8 million new HIV infections (95% uncertainty interval 1.7 million to 2.1 million), 29.2 million prevalent HIV cases (28.1 to 31.7), and 1.3 million HIV deaths (1.3 to 1.5). At the peak of the epidemic in 2005, HIV caused 1.7 million deaths (1.6 million to 1.9 million). Concentrated epidemics in Latin America and eastern Europe are substantially smaller than previously estimated. Through interventions including PMTCT and ART, 19.1 million life-years (16.6 million to 21.5 million) have been saved, 70.3% (65.4 to 76.1) in developing countries. From 2000 to 2011, the ratio of development assistance for health for HIV to years of life saved through intervention was US$ 4498 in developing countries. Including in HIV-positive individuals, all-form tuberculosis incidence was 7.5 million (7.4 million to 7.7 million), prevalence was 11.9 million (11.6 million to 12.2 million), and number of deaths was 1.4 million (1.3 million to 1.5 million) in 2013. In the same year and in only individuals who were HIV-negative, all-form tuberculosis incidence was 7.1 million (6.9 million to 7.3 million), prevalence was 11.2 million (10.8 million to 11.6 million), and number of deaths was 1.3 million (1.2 million to 1.4 million). Annualised rates of change (ARC) for incidence, prevalence, and death became negative after 2000. Tuberculosis in HIV-negative individuals disproportionately occurs in men and boys (versus women and girls); 64.0% of cases (63.6 to 64.3) and 64.7% of deaths (60.8 to 70.3). Globally, malaria cases and deaths grew rapidly from 1990 reaching a peak of 232 million cases (143 million to 387 million) in 2003 and 1.2 million deaths (1.1 million to 1.4 million) in 2004. Since 2004, child deaths from malaria in sub-Saharan Africa have decreased by 31.5% (15.7 to 44.1). Outside of Africa, malaria mortality has been steadily decreasing since 1990.

Interpretation: Our estimates of the number of people living with HIV are 18.7% smaller than UNAIDS's estimates in 2012. The number of people living with malaria is larger than estimated by WHO. The number of people living with HIV, tuberculosis, or malaria have all decreased since 2000. At the global level, upward trends for malaria and HIV deaths have been reversed and declines in tuberculosis deaths have accelerated. 101 countries (74 of which are developing) still have increasing HIV incidence. Substantial progress since the Millennium Declaration is an encouraging sign of the effect of global action.

Abstract  Full-text [free] access

Editor’s notes: The Global Burden of Disease (GBD) study uses standard methods to compare and track over time national distributions of deaths by cause, and the prevalence of disease and disability.  This detailed report focuses on HIV, TB and Malaria. It presents regional summaries of incidence, prevalence and mortality rates, and national estimates of the number of male and female deaths and new infections. Point estimates are shown for 2013, and annualised rates of change for 1990-2000 and 2000-2013. These highlight the contrasting trends in disease impact before and after the formulation of the Millennium Development Goal to combat these diseases.  The global peak of HIV mortality occurred in 2005, but regional annualised rates of change for 2000-2013 indicate that HIV deaths are still increasing significantly in east Asia, southern Africa, and most rapidly in eastern Europe.

The GBD 2013 global estimates of new infections and deaths agree closely with the corresponding estimates made by UNAIDS. But there are significant differences in the respective estimates of the number of people currently living with HIV (UNAIDS estimates are some 18% higher), and historical trends in AIDS deaths, with UNAIDS judging that the recent fall has been steeper. These differences are attributed primarily to methods used in the GBD study to ensure that the sum of deaths from specific causes fits the estimated all cause total, and to varying assumptions about historical survival patterns following HIV infection. 

It may be worthwhile to look at a comment by Michel Sidibé, Mark Dybul, and Deborah Birx in the Lancet on MDG 6 and beyond: from halting and reversing AIDS to ending the epidemic which refers to this study.

Epidemiology
Afghanistan, Albania, Algeria, Andorra, Angola, Antigua and Barbuda, Argentina, Australia, Austria, Bahamas, Bahrain, Bangladesh, Barbados, Belarus, Belgium, Belize, Benin, Bhutan, Bolivia, Bosnia and Herzegovina, Botswana, Brazil, Bulgaria, Burkina Faso, Burundi, Cambodia, Cameroon, Canada, Cape Verde, Central African Republic, Chad, Chile, China, Colombia, Comoros, Congo, Costa Rica, Côte d'Ivoire, Croatia, Cuba, Cyprus, Czech Republic, Democratic People's Republic of Korea, Democratic Republic of the Congo, Democratic Republic of Timor-Leste, Denmark, Djibouti, Dominica, Dominican Republic, Ecuador, Egypt, El Salvador, Equatorial Guinea, Eritrea, Estonia, Ethiopia, Fiji, Finland, France, Gabon, Gambia, Germany, Ghana, Greece, Grenada, Guatemala, Guinea, Guinea-Bissau, Guyana, Haiti, Honduras, Hungary, Iceland, India, Indonesia, Iran (Islamic Republic of), Iraq, Ireland, Israel, Italy, Jamaica, Jordan, Kazakhstan, Kenya, Kiribati, Kuwait, Kyrgyzstan, Lao People's Democratic Republic, Latvia, Lebanon, Lesotho, Liberia, Libyan Arab Jamahiriya, Lithuania, Luxembourg, Madagascar, Malawi, Malaysia, Maldives, Mali, Malta, Marshall Islands, Mauritania, Mauritius, Mexico, Micronesia (Federated States of), Monaco, Mongolia, Morocco, Mozambique, Myanmar, Namibia, Nepal, Netherlands, New Zealand, Nicaragua, Niger, Nigeria, Norway, Oman, Pakistan, Palestinian Territory, Occupied, Panama, Papua New Guinea, Paraguay, Peru, Philippines, Poland, Portugal, Qatar, Romania, Russian Federation, Rwanda, Saint Lucia, Saint Vincent and the Grenadines, Samoa, Sao Tome and Principe, Saudi Arabia, Senegal, Serbia and Montenegro, Seychelles, Sierra Leone, Slovakia, Slovenia, Solomon Islands, Somalia, South Africa, Spain, Sri Lanka, Sudan, Suriname, Swaziland, Sweden, Switzerland, Syrian Arab Republic, Taiwan, Tajikistan, Thailand, Togo, Tonga, Trinidad and Tobago, Tunisia, Turkey, Turkmenistan, Uganda, Ukraine, United States of America, Uruguay, Uzbekistan, Vanuatu, Venezuela, Viet Nam, Yemen, Zimbabwe
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Model estimates large global burden of childhood tuberculosis infection and potentially preventable future tuberculosis disease

Burden of childhood tuberculosis in 22 high-burden countries: a mathematical modelling study.

Dodd PJ, Gardiner E, Coghlan R, Seddon JA. Lancet Glob Health. 2014 Aug;2(8):e453-9. doi: 10.1016/S2214-109X(14)70245-1. Epub 2014 Jul 8.

Background: Confirmation of a diagnosis of tuberculosis in children (aged <15 years) is challenging; under-reporting can result even when children do present to health services. Direct incidence estimates are unavailable, and WHO estimates build on paediatric notifications, with adjustment for incomplete surveillance by the same factor as adult notifications. We aimed to estimate the incidence of infection and disease in children, the prevalence of infection, and household exposure in the 22 countries with a high burden of the disease.

Methods: Within a mechanistic mathematical model, we combined estimates of adult tuberculosis prevalence in 2010, with aspects of the natural history of paediatric tuberculosis. In a household model, we estimated household exposure and infection. We accounted for the effects of age, BCG vaccination, and HIV infection. Additionally, we tested sensitivity to key structural assumptions by repeating all analyses without variation in BCG efficacy by latitude.

Findings: The median number of children estimated to be sharing a household with an individual with infectious tuberculosis in 2010 was 15 319 701 (IQR 13 766 297-17 061 821). In 2010, the median number of Mycobacterium tuberculosis infections in children was 7 591 759 (5 800 053-9 969 780), and 650 977 children (424 871-983 118) developed disease. Cumulative exposure meant that the median number of children with latent infection in 2010 was 53 234 854 (41 111 669-68 959 804). The model suggests that 35% (23-54) of paediatric cases of tuberculosis in the 15 countries reporting notifications by age in 2010 were detected. India is predicted to account for 27% (22-33) of the total burden of paediatric tuberculosis in the 22 countries. The predicted proportion of tuberculosis burden in children for each country correlated with incidence, varying between 4% and 21%.

Interpretation: Our model has shown that the incidence of paediatric tuberculosis is higher than the number of notifications, particularly in young children. Estimates of current household exposure and cumulative infection suggest an enormous opportunity for preventive treatment.

Abstract  Full-text [free] access 

Editor’s notes: Estimating the burden of childhood tuberculosis has been largely neglected until recently. Children with tuberculosis rarely transmit and therefore from a control perspective, childhood tuberculosis does not notably contribute to the continuation of the tuberculosis epidemic. This modelling paper attempts to estimate the global burden of childhood tuberculosis infection and disease. Incidence estimates are made by using adult tuberculosis prevalence data to tackle the known limitations of using paediatric notification data. A second model estimates the prevalence of infection in children and household exposure, ignoring exposure outside of the household.  As with all mathematical model predictions, precision of estimates are dependent on the data used as inputs in the model. Despite these limitations, the paper draws attention to the fact that the burden of childhood tuberculosis infection and disease is significant and reflects failure of tuberculosis control in the 22 high-burden countries. The paper also highlights the fact that household contact tracing and preventive therapy in tuberculosis-exposed children could substantially reduce future tuberculosis-related morbidity.

Avoid TB deaths
Comorbidity, Epidemiology
Africa, Asia, Latin America
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