Articles tagged as "Ethiopia"

Adolescent adherence to antiretroviral therapy: what matters?

Factors associated with adherence to antiretroviral therapy among adolescents living with HIV/AIDS in low- and middle-income countries: a systematic review.

Hudelson C, Cluver L. AIDS Care. 2015 Feb 23:1-12. [Epub ahead of print]

Adolescents living in low- and middle-income countries (LMICs) are disproportionately burdened by the global HIV/AIDS pandemic. Maintaining medication adherence is vital to ensuring that adolescents living with HIV/AIDS receive the benefits of antiretroviral therapy (ART), although this group faces unique challenges to adherence. Knowledge of the factors influencing adherence among people during this unique developmental period is needed to develop more targeted and effective adherence-promoting strategies. This systematic review summarizes the literature on quantitative observational studies examining correlates, including risk and resilience-promoting factors, of ART adherence among adolescents living with HIV/AIDS in LMICs. A systematic search of major electronic databases, conference-specific databases, gray literature, and reference lists of relevant reviews and documents was conducted in May 2014. Included studies examined relationships between at least one factor and ART adherence as an outcome and were conducted in primarily an adolescent population (age 10-19) in LMICs. The search identified 7948 unique citations from which 15 studies fit the inclusion criteria. These 15 studies identified 35 factors significantly associated with ART adherence representing a total of 4363 participants across nine different LMICs. Relevant studies revealed few consistent relationships between measured factors and adherence while highlighting potentially important themes for ART adherence including the impact of (1) adolescent factors such as gender and knowledge of serostatus, (2) family structure, (3) the burdensome ART regimens, route of administration, and attitudes about medication, and (4) health care and environmental factors, such as rural versus urban location and missed clinic appointments. Rates of adherence across studies ranged from 16% to 99%. This review identifies unique factors significantly related to ART adherence among adolescents living in LMICs. More research using longitudinal designs and rigorous measures of adherence is required in order to identify the range of factors influencing ART adherence as adolescents living with HIV/AIDS in LMICs grow into adulthood.

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Editor’s notes: Expanded access to antiretroviral therapy (ART) and scale-up of programmes to prevent mother-to-child HIV transmission has resulted in the burden of paediatric HIV infection shifting onto adolescents, in low- and middle-income countries. Adolescents and young adults account for 41% of incident infections globally and are the only age group for which AIDS-associated deaths have risen in the past decade.

As the number of adolescents on ART increases, sustaining optimal adherence has emerged as the key challenge. While there are limited adolescent-specific data available, estimates of ART adherence suggest that adolescents have much poorer adherence than adults. This leads to increased risk of disease progression, transmission to sexual partners and antiretroviral drug resistance.

There is a growing body of literature that has examined factors affecting adherence, but to date the focus has been on adults and young children. Therefore, this systematic review of factors associated with good and suboptimal adherence specifically among adolescents aged 10 to 19 years, is timely.

There were a diverse range of factors associated with adherence across the fifteen studies considered. These include knowledge of serostatus, the influence of family structure, burdensome regimens, route of administration (caregiver giving medication versus adolescent self-medicating), and attitudes about medication and missed appointments. These factors likely interact with the complexities faced during adolescence to increase the risk of suboptimal adherence.   

The studies considered in this review had significant weaknesses. Firstly, most studies were cross-sectional. Therefore the extent to which causality between the considered factors and adherence can be inferred is limited. Secondly, not all studies reported on the strengths of the relationship between the factors and adherence or accounted for confounding. Thirdly, the method of measuring adherence varied between studies. Only one study in the review used a gold standard, objective treatment outcome measure, HIV viral load.

Notwithstanding these limitations, this is the first study to examine correlates of adherence to ART in adolescence. Although there were few consistent relationships between these factors and adherence, the study does suggest potential activities to improve adherence.

Given the central role of adolescents in determining the trajectory of the HIV epidemic, there is a need for more rigorous research to define factors affecting adherence behaviours among adolescents. Programmes addressing important risk- and resilience-promoting factors such as caregiver support and less burdensome regimens have potential to improve adherence. 

Africa, Asia, Europe, Latin America
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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.

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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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Disease-specific Global Fund grants may be preventing the realisation of system-wide synergies for increased human resources for health

Global Fund investments in human resources for health: innovation and missed opportunities for health systems strengthening.

Bowser D, Sparkes SP, Mitchell A, Bossert TJ, Bärnighausen T, Gedik G, Atun R. Health Policy Plan. 2014 Dec;29(8):986-97. doi: 10.1093/heapol/czt080. Epub 2013 Nov 6.

Background: Since the early 2000s, there have been large increases in donor financing of human resources for health (HRH), yet few studies have examined their effects on health systems.

Objective: To determine the scope and impact of investments in HRH by the Global Fund to Fight AIDS, Tuberculosis and Malaria (Global Fund), the largest investor in HRH outside national governments.

Methods: We used mixed research methodology to analyse budget allocations and expenditures for HRH, including training, for 138 countries receiving money from the Global Fund during funding rounds 1-7. From these aggregate figures, we then identified 27 countries with the largest funding for human resources and training and examined all HRH-related performance indicators tracked in Global Fund grant reports. We used the results of these quantitative analyses to select six countries with substantial funding and varied characteristics-representing different regions and income levels for further in-depth study: Bangladesh (South and West Asia, low income), Ethiopia (Eastern Africa, low income), Honduras (Latin America, lower-middle income), Indonesia (South and West Asia, lower-middle income), Malawi (Southern Africa, low income) and Ukraine (Eastern Europe and Central Asia, upper-middle income). We used qualitative methods to gather information in each of the six countries through 159 interviews with key informants from 83 organizations. Using comparative case-study analysis, we examined Global Fund's interactions with other donors, as well as its HRH support and co-ordination within national health systems.

Results: Around US$1.4 billion (23% of total US$5.1 billion) of grant funding was allocated to HRH by the 138 Global Fund recipient countries. In funding rounds 1-7, the six countries we studied in detail were awarded a total of 47 grants amounting to US$1.2 billion and HRH budgets of US$276 million, of which approximately half were invested in disease-focused in-service and short-term training activities. Countries employed a variety of mechanisms including salary top-ups, performance incentives, extra compensation and contracting of workers for part-time work, to pay health workers using Global Fund financing. Global Fund support for training and salary support was not co-ordinated with national strategic plans and there were major deficiencies in the data collected by the Global Fund to track HRH financing and to provide meaningful assessments of health system performance.

Conclusion: The narrow disease focus and lack of co-ordination with national governments call into question the efficiency of funding and sustainability of Global Fund investments in HRH and their effectiveness in strengthening recipient countries' health systems. The lessons that emerge from this analysis can be used by both the Global Fund and other donors to improve co-ordination of investments and the effectiveness of programmes in recipient countries.

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Editor’s notes: This study describes Global Fund’s budget allocations, expenditures and specific activities on human resources for health (HRH) from 2002 to 2010. The authors were particularly interested in exploring whether and how these investments contributed to health system strengthening through a more detailed qualitative analysis of six geographically and programmatically different countries.  

They find that the 27 countries with the largest budgeted HRH expenditures allocated some 29.6% to HRH, and had a ratio of 1.35 health workers trained in comparison to the total national health workforce, suggesting duplication of training activities and programme inefficiency. This reflects the confirmed lack of coordination with national HRH training programmes that the authors documented, particularly in Ethiopia, Bangladesh and Malawi. In terms of coordinating HRH salary support and financing plans, only Honduras and Malawi had developed plans for absorbing some of the health workers that were being covered by Global Fund grants. In other countries, the top-ups and monetary compensation/ incentives funded through Global Fund grants to increase retention and motivation, were considered short-term and would not be sustained. Of the six country case studies, it is only in Malawi that the Global Fund coordinated its efforts with the national HRH strategy and other donor programmes.

The study highlights the need for a paradigm shift away from disease-focused grants to co-investments in HIV, tuberculosis and malaria that would allow the realisation of remarkable synergies and efficiency gains.

Africa, Asia, Europe, Latin America
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Can community based health care form part of a wider primary health care strategy in sub-Saharan Africa?

Integration of community home based care programmes within national primary health care revitalisation strategies in Ethiopia, Malawi, South-Africa and Zambia: a comparative assessment.

Aantjes C, Quinlan T, Bunders J. Global Health. 2014 Dec 11;10(1):85. [Epub ahead of print]

Background: In 2008, the WHO facilitated the primary health care (PHC) revitalisation agenda. The purpose was to strengthen African health systems in order to address communicable and non-communicable diseases. Our aim was to assess the position of civil society-led community home based care programmes (CHBC), which serve the needs of patients with HIV, within this agenda. We examined how their roles and place in health systems evolved, and the prospects for these programmes in national policies and strategies to revitalise PHC, as new health care demands arise.

Methods: The study was conducted in Ethiopia, Malawi, South Africa and Zambia and used an historical, comparative research design. We used purposive sampling in the selection of countries and case studies of CHBC programmes. Qualitative methods included semi-structured interviews, focus group discussions, service observation and community mapping exercises. Quantitative methods included questionnaire surveys.

Results: The capacity of PHC services increased rapidly in the mid-to-late 2000s via CHBC programme facilitation of community mobilisation and participation in primary care services and the exceptional investments for HIV/AIDS. CHBC programmes diversified their services in response to the changing health and social care needs of patients on lifelong anti-retroviral therapy and there is a general trend to extend service delivery beyond HIV-infected patients. We observed similarities in the way the governments of South Africa, Malawi and Zambia are integrating CHBC programmes into PHC by making PHC facilities the focal point for management and state-paid community health workers responsible for the supervision of community-based activities. Contextual differences were found between Ethiopia, South Africa, Malawi and Zambia, whereby the policy direction of the latter two countries is to have in place structures and mechanisms that actively connect health and social welfare interventions from governmental and non-governmental actors.

Conclusions: Countries may differ in the means to integrate and co-ordinate government and civil society agencies but the net result is expanded PHC capacity. In a context of changing health care demands, CHBC programmes are a vital mechanism for the delivery of primary health and social welfare services.

Abstract  Full-text [free] access

Editor’s notes: This paper presents a comprehensive overview of the integration of community home based care (CHBC) with primary health care (PHC) strategies in four countries in sub-Saharan Africa. It emphasises the co-ordination of efforts between government and civil society. Using a multi method approach drawing on surveys, key informant interviews, focus group discussions and in-depth interviews the authors sought to gain an historical perspective on the changing form and content of CHBC and PHC in Ethiopia, Malawi, South Africa and Zambia. They focused on programmes that had been active for more than 10 years, were nationally representative and offered diversity of care. Their findings reveal a commitment to integration of care within PHC strategies in all the countries. This reflects the recent call by WHO to revitalise primary health care approaches in developing countries. The authors identified similarities across the countries, especially government commitment to revitalise PHC, a strong presence of actors providing CHBC, and the extension of focus beyond one disease such as HIV to the care and support for people with chronic conditions. They also identified three different approaches taken. These included supervision by the government (Malawi, Zambia), contracting (South Africa) and referral (Ethiopia). This reveals that approaches to integration need to be context-driven. This is a very useful paper to understand how HIV care is now being integrated into broader medical and social care and lessons learned from innovative HIV care are being applied more widely and in a more coordinated way.

Africa
Ethiopia, Malawi, South Africa, Zambia
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Antiretroviral therapy alone not enough to reduce TB incidence where HIV- and TB- prevalence is high

Incidence of HIV-associated tuberculosis among individuals taking combination antiretroviral therapy: a systematic review and meta-analysis.

Kufa T, Mabuto T, Muchiri E, Charalambous S, Rosillon D, Churchyard G, Harris RC. PLoS One. 2014 Nov 13;9(11):e111209. doi: 10.1371/journal.pone.0111209. eCollection 2014.

Background: Knowledge of tuberculosis incidence and associated factors is required for the development and evaluation of strategies to reduce the burden of HIV-associated tuberculosis.

Methods: Systematic literature review and meta-analysis of tuberculosis incidence rates among HIV-infected individuals taking combination antiretroviral therapy.

Results: From PubMed, EMBASE and Global Index Medicus databases, 42 papers describing 43 cohorts (32 from high/intermediate and 11 from low tuberculosis burden settings) were included in the qualitative review and 33 in the quantitative review. Cohorts from high/intermediate burden settings were smaller in size, had lower median CD4 cell counts at study entry and fewer person-years of follow up. Tuberculosis incidence rates were higher in studies from sub-Saharan Africa and from World Bank low/middle income countries. Tuberculosis incidence rates decreased with increasing CD4 count at study entry and duration on combination antiretroviral therapy. Summary estimates of tuberculosis incidence among individuals on combination antiretroviral therapy were higher for cohorts from high/intermediate burden settings compared to those from the low tuberculosis burden settings (4.17 per 100 person-years [95% Confidence Interval (CI) 3.39-5.14 per 100 person-years] vs. 0.4 per 100 person-years [95% CI 0.23-0.69 per 100 person-years]) with significant heterogeneity observed between the studies.

Conclusions: Tuberculosis incidence rates were high among individuals on combination antiretroviral therapy in high/intermediate burden settings. Interventions to prevent tuberculosis in this population should address geographical, socioeconomic and individual factors such as low CD4 counts and prior history of tuberculosis.

Abstract Full-text [free] access

Editor’s notes: This systematic review and meta-analysis looks at tuberculosis (TB) incidence rates among adults living with HIV on antiretroviral treatment (ART). The review reinforces and quantifies what we already know about the disparities between low-burden and high-burden settings. TB incidence rates in high and intermediate burden settings are ten times higher than those in low burden settings.

The authors draw attention to the need for implementation of programmes that address the social determinants of TB. Low socio-economic conditions are associated with higher TB incidence rates in individuals on ART. Interestingly, the meta-analysis found that TB incidence rates were higher among individuals on ART who had a previous history of TB, than individuals who did not have a history of previous TB. The epidemiological association between previous TB treatment and active TB was one of the foundations for the emphasis on case retention and cure rates with the Directly Observed Treatment, Short-Course (DOTS) strategy. Yet prevalence surveys conducted in Zimbabwe, South Africa and Zambia in the pre-ART and early ART era did not find an association between a history of previous TB and prevalent active undiagnosed TB in individuals living with HIV. The finding from this meta-analysis suggests that individuals on ART are now surviving long enough to develop recurrent TB disease.

The overall message of the study is that ART alone is not sufficient to reduce TB incidence in high HIV prevalence settings. Additional strategies are required to prevent TB focussing on individuals with low CD4 counts, a history of previous TB disease and people who have recently initiated ART.

Avoid TB deaths
Africa, Asia, Europe, Northern America
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Facility-level costs for antiretroviral therapy are much lower than previously understood

Multi-country analysis of treatment costs for HIV/AIDS (MATCH): facility-level ART unit cost analysis in Ethiopia, Malawi, Rwanda, South Africa and Zambia.

Tagar E, Sundaram M, Condliffe K, Matatiyo B, Chimbwandira F, Chilima B, Mwanamanga R, Moyo C, Chitah BM, Nyemazi JP, Assefa Y, Pillay Y, Mayer S, Shear L, Dain M, Hurley R, Kumar R, McCarthy T, Batra P, Gwinnell D, Diamond S, Over M. PLoS One. 2014 Nov 12;9(11):e108304. doi: 10.1371/journal.pone.0108304. eCollection 2014.

Background: Today's uncertain HIV funding landscape threatens to slow progress towards treatment goals. Understanding the costs of antiretroviral therapy (ART) will be essential for governments to make informed policy decisions about the pace of scale-up under the 2013 WHO HIV Treatment Guidelines, which increase the number of people eligible for treatment from 17.6 million to 28.6 million. The study presented here is one of the largest of its kind and the first to describe the facility-level cost of ART in a random sample of facilities in Ethiopia, Malawi, Rwanda, South Africa and Zambia.

Methods & Findings: In 2010-2011, comprehensive data on one year of facility-level ART costs and patient outcomes were collected from 161 facilities, selected using stratified random sampling. Overall, facility-level ART costs were significantly lower than expected in four of the five countries, with a simple average of $208 per patient-year (ppy) across Ethiopia, Malawi, Rwanda and Zambia. Costs were higher in South Africa, at $682 ppy. This included medications, laboratory services, direct and indirect personnel, patient support, equipment and administrative services. Facilities demonstrated the ability to retain patients alive and on treatment at these costs, although outcomes for established patients (2-8% annual loss to follow-up or death) were better than outcomes for new patients in their first year of ART (77-95% alive and on treatment).

Conclusions: This study illustrated that the facility-level costs of ART are lower than previously understood in these five countries. While limitations must be considered, and costs will vary across countries, this suggests that expanded treatment coverage may be affordable. Further research is needed to understand investment costs of treatment scale-up, non-facility costs and opportunities for more efficient resource allocation.

Abstract Full-text [free] access

Editor’s notes: This paper describes the facility-level costs for antiretroviral therapy (ART) delivery in 161 facilities across five countries. The scale of this study is impressive. At 161 facilities, it is one of the largest existing evaluations of facility-level costs for delivering ART. Collecting detailed cost data is a time- and resource-intensive process, and there is remarkable value in this quantity of cost data being made available.

The results are also surprising. The average cost for ART at the facility level in four of five countries ($208 per person per year) is consistently much lower than previously understood. Primary costing studies in low- and middle-income settings typically find some level of inconsistency between facilities, reflecting room to improve efficiency. This study found more variation in South Africa than in other settings, but relatively little variation overall. It would be interesting to find out in more detail whether this was a function of missing data, or whether the facilities included in the analysis were consistently efficient. If the latter, this may be an indication of improving efficiency in delivery of HIV treatment services.

The most exciting outcome from this study is the low costs found across settings. A number of existing studies of ART costs, all published between 2004-2008, find average facility costs ranging from $650 to $1000 per person, per year. The authors explain their lower costs as a reflection of reduced ART drug prices over the last ten years. Such a dramatic drop in costs is encouraging, particularly in the context of current efforts to expand access to ART.

Africa
Ethiopia, Malawi, Rwanda, South Africa, Zambia
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More, older people living with HIV, but how many more?

Increasing trends in HIV prevalence among people aged 50 years and older: evidence from estimates and survey data.

Mahy M, Autenrieth CS, Stanecki K, Wynd S. AIDS. 2014 Sep 12. [Epub ahead of print]

Objective: To present the most recent 2013 UNAIDS estimates of HIV prevalence among people aged 50 years and older, and to validate these estimates using data from national household surveys.

Design: Modelled estimates of HIV prevalence were validated against nationally representative household survey measures of HIV prevalence.

Methods: The UNAIDS 2013 HIV estimates were used to compute HIV prevalence and number of people living with HIV aged 50 years and older. Sex-specific HIV-prevalence rates by 5-year age groups were calculated from nationally representative household surveys conducted between 2003 and 2013, and were compared to prevalence rates from the modelled estimates. The ratios of the prevalence rates from the two sources were analysed.

Results: In 2013, an estimated 4.2 million (4.0-4.5 million) people aged 50 years and older were living with HIV. The global HIV prevalence among older individuals more than doubled in almost all the 5-year age groups since 1995. There was a relatively good agreement between the modelled HIV-prevalence rates and the survey-based rates among men and women aged 50-54 years (0.90 and 0.98 median ratio, respectively), whereas for 55-59-year-olds, the differences were more notable (ratios of 0.63 for men and 0.9 for women).

Conclusion: Both data sources suggest HIV-prevalence rates among people aged over 50 have increased steadily in recent years. Care and treatment services need to address the specific needs of older people living with HIV. Action is needed to incorporate older age groups into HIV surveillance systems.

Abstract access 

Editor’s notes: According to the most recent estimates, the global number of people above age 50 years and living with HIV, has more than doubled since the mid-1990s. In southern Africa, it has more than tripled. These numbers are expected to increase further as treatment programmes continue to expand. This study by the UNAIDS secretariat, underscores the numeric importance of this population subgroup. Above all, it highlights how little we know about the epidemic in older adults. The authors compare UNAIDS (modelled) HIV prevalence estimates with those from nationally representative surveys. They find good correspondence among 50-54 year-old men and women. The discrepancy between the two sources are more pronounced above age 54 years where the UNAIDS figures tend to fall short of the empirical estimates. This is particularly the case for men. HIV prevalence estimates among older women are rather scarce as surveys and data collection at antenatal clinics typically focus on women of reproductive age. Longer than expected survival of people living with HIV and higher than anticipated HIV incidence at older ages, could explain the discrepancy between the estimates. But we need more and better data about these age groups to be in a position to adjudicate between these explanations.

Epidemiology
Africa
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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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Hunger hinders antiretroviral therapy adherence

Does food insecurity undermine adherence to antiretroviral therapy? A systematic review.

Singer AW, Weiser SD, McCoy SI. AIDS Behav. 2014 Aug 6. [Epub ahead of print]

A growing body of research has identified food insecurity as a barrier to antiretroviral therapy (ART) adherence. We systematically reviewed and summarized the quantitative literature on food insecurity or food assistance and ART adherence. We identified nineteen analyses from eighteen distinct studies examining food insecurity and ART adherence. Of the thirteen studies that presented an adjusted effect estimate for the relationship between food insecurity and ART adherence, nine found a statistically significant association between food insecurity and sub-optimal ART adherence. Four studies examined the association between food assistance and ART adherence, and three found that ART adherence was significantly better among food assistance recipients than non-recipients. Across diverse populations, food insecurity is an important barrier to ART adherence, and food assistance appears to be a promising intervention strategy to improve ART adherence among persons living with HIV. Additional research is needed to determine the effectiveness and cost-effectiveness of food assistance in improving ART adherence and other clinical outcomes among people living with HIV in the era of widespread and long-term treatment.

Abstract access 

Editor’s notes: A number of qualitative studies have found that a lack of food is given as a reason for non-adherence to anti-retroviral therapy (ART). The authors wanted to see if quantitative studies on food security and adherence supported this view. As with many systematic reviews the number of quantitative studies included in the final analysis was small: fourteen. However, the majority of these studies did find an association between the availability of food and adherence. The authors very carefully describe the difference methods used to measure both food security and ART adherence.  These findings show both the wide range of methods used for measurement and definitions of adherence and food security, which made comparisons difficult. So, while the authors did find that food insecurity is a barrier to adherence, they could not say why. Given that food insecurity may be a threat to adherence for the some of the increasing numbers of people starting ART, further research is urgently needed. We need to understand more about the association between food and ART adherence. 

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