Articles tagged as "Republic of Korea"

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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How do we know which activities make a difference to HIV prevention?

Editor’s notes: In order to be fairly certain that an intervention is responsible for changes in HIV or HIV-related behaviours, the gold standard is randomization. This allows for fair comparisons between groups, since factors that might alter the outcomes will be more or less equally balanced between the study groups.  This is true whether such confounding factors are expected, but also importantly, even those factors that are unknown, unexpected and unmeasured will also be balanced between the arms. 

A second key determinant of high quality research is to use an approach that maximizes full engagement and follow-up of participants in the study.  One such approach that is widely recognized is to use Good Participatory Practice.  

Rhodes and colleagues study condom promotion and HIV testing among the Hispanic/Latino community of gay men and other men who have sex with men in North Carolina, USA.  Although gay men and other men who have sex with men represent approximately 4% of the adult male population in the United States of America, they account for more than 80% of new HIV infections among men.  Around one quarter of gay men and other men who have sex with men are Hispanic or Latino.  The authors therefore wanted to use research to make a difference to the HIV burden of the Hispanic/Latino gay men and other men who have sex with men community in North Carolina, USA.  They found that despite the impact of HIV on Hispanic/ Latino gay men and other men who have sex with men, they were only able to identify one evidence-based behavioural HIV prevention programme focussed on this population.

The authors used an extensive community based participatory research partnership, whose members represented the Hispanic/ Latino gay men and other men who have sex with men community, AIDS service organizations, Hispanic/Latino-serving community organizations, and universities to develop, implement, and evaluate a Spanish-language, small group intervention designed to increase condom use and HIV testing among Hispanic/Latino gay men and other men who have sex with men (HOLA en Grupos).

304 participants were randomly allocated to the HOLA en Grupos intervention, or to a general health education comparison intervention having the same number of sessions (4) and duration (16 hours in total) that focussed on prostate, lung, and colorectal cancers; diabetes; high cholesterol; cardiovascular disease; and alcohol misuse. These topics for the control group were identified on the basis of identified needs and priorities of Hispanic/Latino gay men and other men who have sex with men.

HOLA en Grupos is grounded on social cognitive theory, empowerment education, and traditional Hispanic/Latino cultural values and includes four interactive modules of four hours each delivered in groups.  Participants in both intervention and control arms received reimbursement for their time, certificates of completion and meals and a celebration at the completion of the course.  In other words this was an intensive intervention that might be hard to replicate in most settings, but it follows very high standards both for developing and conducting the research and also for determining the impact of the intervention.

The intervention was associated with a large effect on both condom usage (four-fold higher in the intervention arm than the control) and HIV test uptake (an astonishing 14-fold higher, reflecting the relatively low testing rate in the control group).

A major limitation in many HIV prevention studies, including this one, is that the outcome is based on reported behaviour.  The challenge is that the real outcome of interest, which is new HIV infections, is relatively rare in almost all communities so that studies have to be huge and expensive, and the large majority of participants in both intervention and control arms do not in fact acquire HIV.  This is in contrast to most studies of treatment, where there are clearly defined biological, standardized measures which many or all participants are likely to reach.  Nonetheless, there are many examples of studies that find changes in reported behaviour that are not associated with biological markers of such change (such as incidence of HIV or other sexually transmitted infections, or pregnancy). 

There are also many observational or ecological studies that report changes in new HIV infections but that cannot truly say why the number of infections fell and whether the interventions used in the study were responsible for the changes.  For example Nwokolo and colleagues report in a short research letter on the dramatic decline in new HIV diagnoses in the large London clinic where they work.  New infections in that clinic, and in fact in other large clinics in London, have dropped by a remarkable 40% from 2015 to 2016, as originally reported in the popular science press before any scientific publication or presentation. The authors of the research letter are suitably cautious about how to account for the impressive decline.  Various systems have been improved over the past few years in this clinic to make it easier to have an HIV test and start treatment immediately.  However, most of the clinic team (and many other commentators) assume that it is also due to the rapid rise in the use of PrEP.  Although it is still not available through the UK National Health Service, the clinic has been at the forefront of encouraging gay men and other men who have sex with men who might benefit from PrEP to purchase it from on-line pharmacies.  The clinic then provides the appropriate monitoring and follow up to ensure that their clients get the best possible PrEP service given the current constraints.  Whatever the cause, we should be celebrating the rapid fall in new HIV infections across London, which is home to a substantial proportion of the new HIV infections in the UK.

The challenges of demonstrating evidence of effectiveness for HIV prevention is also felt among black women in the USA.  Although they have the highest burden of HIV among women in the USA, the incidence rates are such that a traditional randomized trial design would need to be huge, and consequently hugely expensive.  Adimora and colleagues consider whether an alternative trial design might be to use data from high HIV incidence settings and then to develop proxies of protection, such as the concentration of a PrEP medicine to infer whether black women are protected.  An alternative that has been proposed for men who have sex with men would be to look for other markers of high risk, such as sexually transmitted infections, reported partners, age, and substance use and estimate the likely risk of HIV acquisition in the absence of PrEP from these parameters.  Then the observed incidence could be compared to this modelled counterfactual, much as was done in the open label extension of the Partners PrEP study in Kenyan and Ugandan sero-different couples.  However, translating risk factors for infection across populations, and even continents when there is such heterogeneity in risk of infection is not at all straightforward.  So there is still plenty to think about and no clear answers yet!

A useful addition to the tool box for designing studies and assessing the effectiveness of interventions, would be better tools for measuring recent infection.  There are several assays all with differing characteristics but increasingly these differences and how they interact with different clades of HIV are becoming clear.  Key determinants for each assay are the mean duration of recent infection (MDRI) estimate (which does seem to vary by clade) and the false recency rate (FRR) which needs to be less than 2% to be considered useful.  Hargrove and colleagues used three different assays to test samples from 101 women who seroconverted during the ZVITAMBO trial.  The MDRI measured using standard cut-off points, were considerably shorter than those published for the general population.  The authors point out that changes in antibody properties among women who have recently given birth or other unspecified physiological states, mean that incidence assays may give different results from those published and expected.  Yet more caution when comparing incidence estimates between studies.  As an endpoint in a comparison between two groups in the same population, the assays are still attractive. Although, given typical MDRIs of around six to nine months, these assays will still need to be embedded in very large samples to give reliable estimates of incidence and statistically significant differences between groups.

This month saw the production of a useful supplement on many aspects of how data from different sources, including incidence assays are used to inform the sophisticated models on which so much HIV planning, programming and financing is based.  An example is Mahiane and colleagues’ paper on the development of a new tool to fit existing programme data into the spectrum suite of models in order to estimate incidence.

Finally in this section, for those who are keen on laboratory studies, Richardson-Harman and colleagues describe the current state of ex-vivo challenge models for assessing potential candidates as microbicides.  In these models, biopsies of rectal, cervical or vaginal tissue, taken during other procedures, or from volunteers, are kept alive in the laboratory.  The tissues can then be challenged with HIV in the presence or absence of potential microbicide products.  The current model works best for rectal tissues, in which infection occurs promptly and consistently, so that the effect of a microbicide can clearly be seen by a reduction in the production of HIV p24 antigen.  However, for cervical and vaginal tissues, the infection (in the absence of any microbicide) was less consistent, slower and lasted longer making it less easy to determine statistical differences between those tissues with microbicide and those without.  Further work of this sort may help to streamline the choice of microbicide or PrEP products that can most sensibly be taken out of the laboratory and into the (almost) real world of clinical trials.

Small-group randomized controlled trial to increase condom use and HIV testing among Hispanic/Latino gay, bisexual, and other men who have sex with men.

Rhodes SD, Alonzo J, Mann L, Song EY, Tanner AE, Arellano JE, Rodriguez-Celedon R, Garcia M, Freeman A, Reboussin BA, Painter TM. Am J Public Health. 2017 Jun;107(6):969-976. doi: 10.2105/AJPH.2017.303814. Epub 2017 Apr 20.

Objectives: To evaluate the HOLA en Grupos intervention, a Spanish-language small-group behavioral HIV prevention intervention designed to increase condom use and HIV testing among Hispanic/Latino gay, bisexual, and other men who have sex with men.

Methods: In 2012 to 2015, we recruited and randomized 304 Hispanic/Latino men who have sex with men, aged 18 to 55 years in North Carolina, to the 4-session HOLA en Grupos intervention or an attention-equivalent general health education comparison intervention. Participants completed structured assessments at baseline and 6-month follow-up. Follow-up retention was 100%.

Results: At follow-up, relative to comparison participants, HOLA en Grupos participants reported increased consistent condom use during the past 3 months (adjusted odds ratio [AOR] = 4.1; 95% confidence interval [CI] = 2.2, 7.9; P < .001) and HIV testing during the past 6 months (AOR = 13.8; 95% CI = 7.6, 25.3; P < .001). HOLA en Grupos participants also reported increased knowledge of HIV (P < .001) and sexually transmitted infections (P < .001); condom use skills (P < .001), self-efficacy (P < .001), expectancies (P < .001), and intentions (P < .001); sexual communication skills (P < .01); and decreased fatalism (P < .001).

Conclusions: The HOLA en Grupos intervention is efficacious for reducing HIV risk behaviors among Hispanic/Latino men who have sex with men.

Abstract access 

Not just PrEP: other reasons for London's HIV decline.

Nwokolo N, Whitlock G, McOwan A. Lancet HIV. 2017 Apr;4(4):e153. doi: 10.1016/S2352-3018(17)30044-9.

The reduction in HIV diagnoses in London in 2016 is attributed to pre-exposure prophylaxis (PrEP). We believe that the causes of the 42% decline seen at our clinic are likely to be multifactorial. 56 Dean Street diagnoses one in four of London's HIV cases, 50% of whom have incident infection (ie, within 4 months of infection). Because of this, and following the results of the START study, we actively recommend treatment at, or close to, diagnosis, reducing the risk of transmission in people who would otherwise be highly infectious.

Abstract access 

US black women and HIV prevention: time for new approaches to clinical trials.

Adimora AA, Cole SR, Eron JJ Clin Infect Dis. 2017 Apr 5. doi: 10.1093/cid/cix313. [Epub ahead of print]. 

Black women bear the highest burden of HIV infection among US women. Tenofovir/ emtricitabine HIV prevention trials among women in Africa have yielded varying results. Ideally, a randomized controlled trial (RCT) among US women would provide data for guidelines for US women's HIV pre-exposure prophylaxis use. However, even among US black women at high risk for HIV infection, sample size requirements for an RCT with HIV incidence as its outcome are prohibitively high. We propose to circumvent this large sample size requirement by evaluating relationships between HIV incidence and drug concentrations measured among participants in traditional phase 3 trials in high incidence settings - and then applying these observations to drug concentrations measured among at risk individuals in lower incidence settings, such as US black women. This strategy could strengthen the evidence base to enable black women to fully benefit from prevention research advances and decrease racial disparities in HIV rates.

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Heightened HIV antibody responses in postpartum women as exemplified by recent infection assays: implications for incidence estimates.

Hargrove JW, van Schalkwyk C, Humphrey JH, Mutasa K, Ntozini R, Owen SM, Masciotra S, Parekh BS, Duong YT, Dobbs T, Kilmarx PH, Gonese E. AIDS Res Hum Retroviruses. 2017 May 24. doi: 10.1089/AID.2016.0319. [Epub ahead of print].

Laboratory assays that identify recent HIV infections are important for assessing impacts of interventions aimed at reducing HIV incidence. Kinetics of HIV humoral responses can vary with inherent assay properties, and between HIV subtypes, populations, and physiological states. They are important in determining mean duration of recent infection (MDRI) for antibody-based assays for detecting recent HIV infections. We determined MDRIs for multi-subtype peptide representing subtypes B, E and D (BED)-capture enzyme immunoassay, limiting antigen (LAg), and Bio-Rad Avidity Incidence (BRAI) assays for 101 seroconverting postpartum women, recruited in Harare from 1997 to 2000 during the Zimbabwe Vitamin A for Mothers and Babies trial, comparing them against published MDRIs estimated from seroconverting cases in the general population. We also compared MDRIs for women who seroconverted either during the first 9 months, or at later stages, postpartum. At cutoffs (C) of 0.8 for BED, 1.5 for LAg, and 40% for BRAI, estimated MDRIs for postpartum mothers were 192, 104, and 144 days, 33%, 32%, and 52% lower than published estimates of 287, 152 and 298 days, respectively, for clade C samples from general populations. Point estimates of MDRI values were 7%-19% shorter for women who seroconverted in the first 9 months postpartum than for those seroconverting later. MDRI values for three HIV incidence biomarkers are longer in the general population than among postpartum women, particularly those who recently gave birth, consistent with heightened immunological activation soon after birth. Our results provide a caution that MDRI may vary significantly between subjects in different physiological states.

Abstract access 

Improvements in Spectrum's fit to program data tool.

Mahiane SG, Marsh K, Grantham K, Crichlow S, Caceres K, Stover J.  AIDS. 2017 Apr;31 Suppl 1:S23-S30. doi: 10.1097/QAD.0000000000001359.

Objective: The Joint United Nations Program on HIV/AIDS-supported Spectrum software package (Glastonbury, Connecticut, USA) is used by most countries worldwide to monitor the HIV epidemic. In Spectrum, HIV incidence trends among adults (aged 15-49 years) are derived by either fitting to seroprevalence surveillance and survey data or generating curves consistent with program and vital registration data, such as historical trends in the number of newly diagnosed infections or people living with HIV and AIDS related deaths. This article describes development and application of the fit to program data (FPD) tool in Joint United Nations Program on HIV/AIDS' 2016 estimates round.

Methods: In the FPD tool, HIV incidence trends are described as a simple or double logistic function. Function parameters are estimated from historical program data on newly reported HIV cases, people living with HIV or AIDS-related deaths. Inputs can be adjusted for proportions undiagnosed or misclassified deaths. Maximum likelihood estimation or minimum chi-squared distance methods are used to identify the best fitting curve. Asymptotic properties of the estimators from these fits are used to estimate uncertainty.

Results: The FPD tool was used to fit incidence for 62 countries in 2016. Maximum likelihood and minimum chi-squared distance methods gave similar results. A double logistic curve adequately described observed trends in all but four countries where a simple logistic curve performed better.

Conclusion: Robust HIV-related program and vital registration data are routinely available in many middle-income and high-income countries, whereas HIV seroprevalence surveillance and survey data may be scarce. In these countries, the FPD tool offers a simpler, improved approach to estimating HIV incidence trends.

Abstract access 

Analytical advances in the ex vivo challenge efficacy assay.

Richardson-Harman N, Parody R, Anton P, McGowan I, Doncel G, Thurman AR, Herrera C, Kordy K, Fox J, Tanner K, Swartz G, Dezzutti CS. AIDS Res Hum Retroviruses. 2017 Apr;33(4):395-403. doi: 10.1089/AID.2016.0073. Epub 2016 Dec 16.

The ex vivo challenge assay is being increasingly used as an efficacy endpoint during early human clinical trials of HIV prevention treatments. There is no standard methodology for the ex vivo challenge assay, although the use of different data collection methods and analytical parameters may impact results and reduce the comparability of findings between trials. In this analysis, we describe the impact of data imputation methods, kit type, testing schedule and tissue type on variability, statistical power, and ex vivo HIV growth kinetics. Data were p24 antigen (pg/ml) measurements collected from clinical trials of candidate microbicides where rectal (n = 502), cervical (n = 88), and vaginal (n = 110) tissues were challenged with HIV-1BaL ex vivo. Imputation of missing data using a nonlinear mixed effect model was found to provide an improved fit compared to imputation using half the limit of detection. The rectal virus growth period was found to be earlier and of a relatively shorter duration than the growth period for cervical and vaginal tissue types. On average, only four rectal tissue challenge assays in each treatment and control group would be needed to find a one log difference in p24 to be significant (alpha = 0.05), but a larger sample size was predicted to be needed for either cervical (n = 21) or vaginal (n = 10) tissue comparisons. Overall, the results indicated that improvements could be made in the design and analysis of the ex vivo challenge assay to provide a more standardized and powerful assay to compare efficacy of microbicide products.

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Phylogenetics - powerful new tools tied to ethical imperatives for key populations

Editor’s notes: There are now well over half a million HIV isolates that have been sequenced and the data stored in public accessible Genbank.  A systematic review by Hassan AS and colleagues of the methods used to define phylogenetic trees and clusters within them demonstrates the importance of using the correct criteria for the hypothesis being tested. Most articles use the pol sequence, since this is what is sequenced for drug resistance testing.  Most analyses have been done using a phylogenetic approach that uses a probability to assess the likelihood that isolates are clustered, and so depends on the cut-off value chosen.  For example, a well-studied outbreak of HIV among drug users in Finland is clearly linked to an earlier outbreak in Sweden, but because the Finnish isolates were collected later, they had already diverged somewhat from the Swedish ones.  If the threshold was set too high, they would not be recognized to be part of the same outbreak.  However for active transmission chains, a high threshold is needed to avoid falsely linking isolates.  There is no consensus on what methods to use, so caution is needed when comparing different studies.

Mark Wainberg, Professor of Medicine and of Microbiology at McGill University and a giant of Canadian HIV science, passed away this month.  So, as a tribute to his work, we have chosen a study from the McGill AIDS Centre by Brenner BG and colleagues.  The team used phylogenetic analysis to classify pre-treatment HIV isolates from 3901 men who have sex with men in Quebec according to the likelihood of being an acute or recent infection and the likelihood of clustering with other isolates.  Over the period from 2002-2015, a larger and larger proportion of the infections in this population could be linked to larger clusters, particularly involving younger men and men with recent infection, many of whom did not know their HIV status.  At least 40% of the onward spread of the epidemic in Quebec can be ascribed to just thirty clusters, varying in size from 20–140 individuals.

Using phylogenetics to understand transmission patterns requires careful attention to ethics, confidentiality and stigmatization.  A study in South Korea by Ahn MY and colleagues aimed to define the risk factors for clustering within clusters among 143 people living with HIV in four cities.  In eight out of the nine clusters identified participants did not report the same risk factors. Clusters were small, eight pairs and one quartet.  In the two tightest clusters, where the isolates were indistinguishable on the sequences examined, one man stated that he had sex with women, but the paired isolate came from another man and in the other pair, both men chose not to disclose their risk factors.  With small studies where information can sometimes be inferred even when not disclosed, it is perhaps not surprising that more than half the participants chose not to report their risk factors.

Other phylogenetic studies this month have explored the evolution of HIV recombination and the spread of different clades in communities in North-Eastern Brazil [Delatorre E et al.] and China.  In the North-Eastern states of Brazil, 72% of HIV isolates were subtype B, but rare subtypes such as D (1%) and CRF02_AG (1%) appear to be spreading within the population rather than being introduced from outside. In China studies from Sichuan [Wang Y et al.], Yunnan [Li Y and colleagues] and Zhejiang [Wang H et al.] have shown new recombinant forms of HIV with elements that suggest that viruses from different countries in the region have combined.  The widening diversity of HIV brings challenges for vaccine development, and potentially for HIV assays, such as those for recent infection that may differ in their sensitivity and specificity between different sub-types.  Understanding the migration of people and their viruses could be useful for providing better services, but careful attention to messaging will be needed to prevent such data from being used to discriminate further against migrants.

The final phylogenetic paper this month also comes from China, where Hao M and colleagues reported a study of students living with HIV in Beijing. The study demonstrated that transmitted drug resistance is still low in this setting, with just 0.8% of 237 students having virus that was resistant to non-nucleoside reverse transcriptase inhibitors that form part of the backbone of first line treatment in China.  A further 1.3% has resistance to protease inhibitors that are used in second line treatment.

Defining HIV-1 transmission clusters based on sequence data: a systematic review and perspectives.

Hassan AS, Pybus OG, Sanders EJ, Albert J, Esbjörnsson J. AIDS. 2017 Mar 28. doi: 10.1097/QAD.0000000000001470. [Epub ahead of print]

Understanding HIV-1 transmission dynamics is relevant to both screening and intervention strategies of HIV-1 infection. Commonly, HIV-1 transmission chains are determined based on sequence similarity assessed either directly from a sequence alignment or by inferring a phylogenetic tree. This review is aimed at both nonexperts interested in understanding and interpreting studies of HIV-1transmission, and experts interested in finding the most appropriate cluster definition for a specific dataset and research question. We start by introducing the concepts and methodologies of how HIV-1 transmission clusters usually have been defined. We then present the results of a systematic review of 105 HIV-1 molecular epidemiology studies summarizing the most popular methods and definitions in the literature. Finally, we offer our perspectives on how HIV-1 transmission clusters can be defined and provide some guidance based on examples from real life datasets.

Abstract access 

Large cluster outbreaks sustain the HIV epidemic among MSM in Quebec.

Brenner BG, Ibanescu RI, Hardy I, Stephens D, Otis J, Moodie E, Grossman Z,Vandamme AM, Roger M, Wainberg MA; and the Montreal PHI, SPOT cohorts. AIDS. 2017 Mar 13;31(5):707-717. doi: 10.1097/QAD.0000000000001383.

Objective: HIV-1 epidemics among MSM remain unchecked despite advances in treatment and prevention paradigms. This study combined viral phylogenetic and behavioural risk data to better understand underlying factors governing the temporal growth of the HIV epidemic among MSM in Quebec (2002-2015).

Methods: Phylogenetic analysis of pol sequences was used to deduce HIV-1transmission dynamics (cluster size, size distribution and growth rate) in first genotypes of treatment-naïve MSM (2002-2015, n = 3901). Low sequence diversity of first genotypes (0-0.44% mixed base calls) was used as an indication of early-stage infection. Behavioural risk data were obtained from the Montreal rapid testing site and primary HIV-1-infection cohorts.

Results: Phylogenetic analyses uncovered high proportion of clustering of new MSM infections. Overall, 27, 45, 48, 53 and 57% of first genotypes within one (singleton, n = 1359), 2-4 (n = 692), 5-9 (n = 367), 10-19 (n = 405) and 20+ (n = 1277) cluster size groups were early infections (<0.44% diversity). Thirty viruses within large 20+ clusters disproportionately fuelled the epidemic, representing 13, 25 and 42% of infections, first genotyped in 2004-2007 (n = 1314), 2008-2011 (n = 1356) and 2012-2015 (n = 1033), respectively. Of note, 35, 21 and 14% of MSM belonging to 20+, 2-19 and one (singleton) cluster groups were under 30 years of age, respectively. Half of persons seen at the rapid testing site (2009-2011, n = 1781) were untested in the prior year. Poor testing propensity was associated with fewer reported partnerships.

Conclusion: Addressing the heterogeneity in transmission dynamics among HIV-1-infected MSM populations may help guide testing, treatment and prevention strategies.

Abstract access 

HIV-1 transmission networks across South Korea.

Ahn MY, Wertheim JO, Kim WJ, Kim SW, Lee JS, Ann HW, Jeon Y, Ahn JY, Song JE, Oh DH, Kim YC, Kim EJ), Jung IY, Kim MH, Jeong W, Jeong SJ, Ku NS, Kim JM, Smith DM, Choi JY. AIDS Res Hum Retroviruses. 2017 Mar 27. doi: 10.1089/aid.2016.0212. [Epub ahead of print]

Molecular epidemiology can help clarify the properties and dynamics of HIV-1 transmission networks in both global and regional scales. We studied 143 HIV-1-infected individuals recruited from four medical centers of three cities in South Korea between April 2013 and May 2014. HIV-1 env V3 sequence data were generated (337-793 bp) and analyzed using a pairwise distance-based clustering approach to infer putative transmission networks. Participants whose viruses were ≤2.0% divergent according to Tamura-Nei 93 genetic distance were defined as clustering. We collected demographic, risk, and clinical data and analyzed these data in relation to clustering. Among 143 participants, we identified nine putative transmission clusters of different sizes (range 2-4 participants). The reported risk factor of participants were concordant in only one network involving two participants, that is, both individuals reported homosexual sex as their risk factor. The participants in the other eight networks did not report concordant risk factors, although they were phylogenetically linked. About half of the participants refused to report their risk factor. Overall, molecular epidemiology provides more information to understand local transmission networks and the risks associated with these networks.

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HIV-1 Genetic diversity in northeastern Brazil: high prevalence of non-B subtypes.

Delatorre E, Couto-Fernandez JC, Bello G.AIDS Res Hum Retroviruses. 2017 Mar 22. doi: 10.1089/AID.2017.0045. [Epub ahead of print]

The Northeastern Brazilian region has experienced a constant increase in the number of newly reported AIDS cases over the last decade, but the genetic diversity of HIV-1 strains currently disseminated in this region remains poorly explored. HIV-1 pol sequences were obtained from 140 patients followed at outpatient clinics from four Northeastern Brazilian states (Alagoas, Bahia, Ceará and Piauí) between 2014 and 2015. Subtype B was the most prevalent HIV-1 clade (72%) detected in the Northeastern region, followed by subtypes F1 (6%), C (5%) and D (1%). The remaining strains (16%) displayed a recombinant structure and were classified as: BF1 (11%), BC (4%), BCF1 (1%) and CRF02_AG-like (1%). The 20 HIV-1 BF1 and BC recombinant sequences detected were distributed among 11 lineages classified as: CRF28/29_BF-like (n = 5), CRF39_BF-like (n = 1), URFs_BF (n = 9) and URFs_BC (n = 5). Non-B subtypes were detected in all Northeastern Brazilian states, but with variable prevalence, ranging from 16% in Ceará to 55% in Alagoas. Phylogenetics analyses support that subtype D and CRF02_AG strains detected in the Northeastern region resulted from the expansion of autochthonous transmission networks, rather than from exogenous introductions from other countries. These results reveal that HIV-1 epidemic spreading in the Northeastern Brazilian region is comprised by multiple subtypes and recombinant strains and that the molecular epidemiologic pattern in this Brazilian region is much more complex than originally estimated.

Abstract access 

Identification of a novel HIV type 1 CRF01_AE/B'/C recombinant isolate in Sichuan, China.

Wang Y, Kong D, Xu W, Li F, Liang S, Feng Y, Zhang F, Shao Y, Ma L. AIDS Res Hum Retroviruses. 2017 Mar 13. doi: 10.1089/aid.2017.0002. [Epub ahead of print]

We report in this study a novel HIV-1 unique recombinant virus (XC2014EU01) isolated from an HIV-positive man who infected through heterosexual sex in Sichuan, China. The near full-length genome analyses showed that XC2014EU01 harbored one subtype B segment in pol region and two subtype C segments in gag-pol region in a CRF01_AE backbone. The unique mosaic structure was distinctly different from the other CRF01_AE/B'/C recombinant forms reported. Phylogenetic tree analyses revealed that the subtype B region originated from a Thailand subtype B' lineage, the subtype C regions were from an India C lineage, and the backbone was from CRF01_AE. XC2014EU01 was still identified as CCR5-tropic, and plasma of XC2014EU01 infected person had the media neutralizing activity. The emergence of XC2014EU01 may increase the complexity of the HIV-1 epidemic among high-risk populations and the difficulty of vaccine research and development.

Abstract access 

Identification of a novel HIV type 1 circulating recombinant form (CRF86_BC) among heterosexuals in Yunnan, China.

Li Y, Miao J, Miao Z, Song Y, Wen M, Zhang Y, Guo S, Zhao Y, Feng Y, Xia X. AIDS Res Hum Retroviruses. 2017 Mar;33(3):279-283. doi: 10.1089/AID.2016.0188. Epub 2016 Oct 18.

In recent years, multiple circulating recombinant forms (CRFs) and unique recombinant forms of human immunodeficiency virus type 1 (HIV-1) have been described in Yunnan, China. Here, we identified a novel HIV-1 CRF (CRF86_BC) isolated from three heterosexuals with no obvious epidemiologic linkage in western Yunnan (Baoshan prefecture) in China. CRF86_BC had a subtype C backbone with four subtype B fragments inserted into the pol, vpr, vpu, env, and nef gene regions, respectively. Furthermore, subregion tree analysis revealed that subtype C backbone originated from an Indian C lineage and subtype B segment inserted was from a Thai B lineage. They are different from previously documented B/C forms in its distinct backbone, inserted fragment size, and break points. This highlighted the importance of continual monitoring of genetic diversity and complexity of HIV-1 strains in this region.

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Near full-length genomic characterization of a novel HIV-1 unique recombinant (CRF55_01B/CRF07_BC) from a Malaysian immigrant worker in Zhejiang, China.

Wang H, Luo P, Zhu H, Wang N, Hu J, Mo Q, Yang Z, Feng Y. AIDS Res Hum Retroviruses. 2017 Mar;33(3):275-278.doi: 10.1089/AID.2016.0100. Epub 2016 Aug 17.

Recombinant forms contribute substantially to the genetic diversity of human immunodeficiency virus type 1 (HIV-1). Here we report a novel HIV-1 recombinant detected from a comprehensive HIV-1 molecular epidemiologic study among cross-border populations in China. Near full-length genome (NFLG) phylogenetic analysis showed that the novel HIV-1 recombinant ZJCIQ15005, which was isolated from a Malaysian immigrant worker in Zhejiang, China, clustered with CRF55_01B reference sequences but set up a distinct branch. Recombinant analysis showed that the NFLG of ZJCIQ15005 composed of CRF55_01B (as the backbone) and CRF07_BC,with 12 recombinant break points observed in the pol, vif, vpr, tat, rev, env,nef, and 3'LTR regions. This is the first detection of a novel HIV-1 recombinant (CRF55_01B/CRF07_BC) in immigrant workers in China. The emergence of this recombinant may increase the complexity of the HIV-1 epidemic in China and suggests the importance of continuous surveillance of the dynamic changes of HIV-1.

Abstract access 

Low rates of transmitted drug resistances among treatment-naive HIV-1 infected students in Beijing, China.

Hao M, Wang J, Xin R, Li X, Hao Y, Chen J, Ye J, Wang Y, He X, Huang C, Lu H. AIDS Res Hum Retroviruses. 2017 Mar 22. doi: 10.1089/AID.2017.0053. [Epub ahead of print]

Beijing has seen a rising epidemic of HIV among students. However, little information was known about the molecular epidemiologic data among HIV-infected students. In this study, the diversity and the prevalence of TDR in pol sequences deriving from 237 HIV-infected students were analyzed. TDR mutations were found in 5 MSM among students. The overall prevalence of TDR in students was 2.1%, comprised of 1.3% to protease inhibitors and 0.8 % to non-nucleoside reverse transcriptase inhibitors. Our finding indicates a low-level prevalence of TDR mutations among students in Beijing.

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Asia, Latin America, Northern America
Brazil, Canada, China, Republic of Korea
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TB still responsible for large proportion of admissions and in-patient deaths among people living with HIV

TB as a cause of hospitalization and in-hospital mortality among people living with HIV worldwide: a systematic review and meta-analysis.

Ford N, Matteelli A, Shubber Z, Hermans S, Meintjes G, Grinsztejn B, Waldrop G, Kranzer K, Doherty M, Getahun H. J Int AIDS Soc. 2016 Jan 12;19(1):20714. doi: 10.7448/IAS.19.1.20714. eCollection 2016.

Introduction: Despite significant progress in improving access to antiretroviral therapy over the past decade, substantial numbers of people living with HIV (PLHIV) in all regions continue to experience severe illness and require hospitalization. We undertook a global review assessing the proportion of hospitalizations and in-hospital deaths because of tuberculosis (TB) in PLHIV.

Methods: Seven databases were searched to identify studies reporting causes of hospitalizations among PLHIV from 1 January 2007 to 31 January 2015 irrespective of age, geographical region or language. The proportion of hospitalizations and in-hospital mortality attributable to TB was estimated using random effects meta-analysis.

Results: From an initial screen of 9049 records, 66 studies were identified, providing data on 35 845 adults and 2792 children across 42 countries. Overall, 17.7% (95% CI 16.0 to 20.2%) of all adult hospitalizations were because of TB, making it the leading cause of hospitalization overall; the proportion of adult hospitalizations because of TB exceeded 10% in all regions except the European region. Of all paediatric hospitalizations, 10.8% (95% CI 7.6 to 13.9%) were because of TB. There was insufficient data among children for analysis by region. In-hospital mortality attributable to TB was 24.9% (95% CI 19.0 to 30.8%) among adults and 30.1% (95% CI 11.2 to 48.9%) among children.

Discussion: TB remains a leading cause of hospitalization and in-hospital death among adults and children living with HIV worldwide.

Abstract  Full-text [free] access

Editor’s notes: The last 30 years have seen radical improvements in outcomes for many people living with HIV. This study reminds us that in some parts of the world HIV-associated infections, tuberculosis (TB) in particular, still have a devastating effect on thousands of lives.

The importance of TB is widely recognised. WHO aim to reduce deaths due to TB by 75% over the next 10 years.  The question remains: do we really know how many people die due to TB?  Death certification has repeatedly been shown to be unreliable, particularly in the parts of the world where TB is most prevalent. Verbal autopsy is used to estimate cause of death in areas with poor notification systems, but poorly differentiates deaths due to TB and other HIV-associated conditions. Similar challenges are faced when counting and classifying morbidity and hospitalisations. Data are sparse, and determining the cause of an admission is not straightforward, even with access to well-maintained hospital records.  

This review, a sub-analysis of data from a broader study of HIV-associated hospital admissions, is by far the largest of its kind. The authors have been rigorous, given the heterogeneity of the studies included, and their findings are sobering. Among adults living with HIV, in all areas except Europe and South America, TB was the cause of 20-33% of admissions, and some 30% of adults and 45% of children who were admitted with TB were thought to have died from it. These findings are limited by the fact that not all reviewed studies reported on mortality and very few stated how causes of death were assigned.

This paper raises more questions than it answers, but they are important questions.  We are left in no doubt that TB is a major contributor to global morbidity and mortality in HIV-positive people, but we need to look closely at how we count and classify ‘TB deaths’ and ‘TB-associated admissions’. The recent systematic review of autopsy studies cited by the authors also found that almost half the TB seen at autopsy was not diagnosed before death. Global autopsy rates are in decline. Without access to more accurate data, how will we know if we’re winning or losing in our efforts to end TB deaths?

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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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CD4 counts at antiretroviral therapy start rising globally, but could do better!

Immunodeficiency at the start of combination antiretroviral therapy in low-,  middle-, and high-income countries.

The IeDEA and ART Cohort Collaborations. J Acquir Immune Defic Syndr 2014 Jan 1;65(1):e8-e16. doi: 10.1097/QAI.0b013e3182a39979.

Objective: To describe the CD4 cell count at the start of combination antiretroviral therapy (cART) in low-income (LIC), lower middle-income (LMIC), upper middle-income (UMIC), and high-income (HIC) countries.

Methods: Patients aged 16 years or older starting cART in a clinic participating in a multicohort collaboration spanning 6 continents (International epidemiological Databases to Evaluate AIDS and ART Cohort Collaboration) were eligible. Multilevel linear regression models were adjusted for age, gender, and calendar year; missing CD4 counts were imputed.

Results: In total, 379 865 patients from 9 LIC, 4 LMIC, 4 UMIC, and 6 HIC were included. In LIC, the median CD4 cell count at cART initiation increased by 83% from 80 to 145 cells/µL between 2002 and 2009. Corresponding increases in LMIC, UMIC, and HIC were from 87 to 155 cells/µL (76% increase), 88 to 135 cells/µL (53%), and 209 to 274 cells/µL (31%). In 2009, compared with LIC, median counts were 13 cells/µL [95% confidence interval (CI): -56 to +30] lower in LMIC, 22 cells/µL (-62 to +18) lower in UMIC, and 112 cells/µL (+75 to +149) higher in HIC. They were 23 cells/µL (95% CI: +18 to +28 cells/µL) higher in women than men. Median counts were 88 cells/µL (95% CI: +35 to +141 cells/µL) higher in countries with an estimated national cART coverage >80%, compared with countries with <40% coverage.

Conclusions: Median CD4 cell counts at the start of cART increased 2000-2009 but remained below 200 cells/µL in LIC and MIC and below 300 cells/µL in HIC. Earlier start of cART will require substantial efforts and resources globally.

Abstract access 

Editor’s notes: In this multi-cohort analysis spanning six continents, median CD4 counts at initiation of combination antiretroviral therapy were substantially higher in high-income compared to low- or middle-income countries. Median CD4 counts at initiation increased between 2002 and 2009 in most countries studied, but these increases were greater in low- and middle-income than high-income countries and were greater among men than women. Baseline CD4 counts in low- and middle-income countries were higher among countries with national antiretroviral therapy coverage of 80% or above. Nevertheless, despite the massive scale-up of antiretroviral therapy in low-income countries since 2002, the increases in median CD4 count at the start of antiretroviral therapy have been modest. Substantial efforts and resources are needed to achieve earlier implementation of antiretroviral therapy globally.

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