Extent to which low-level use of antiretroviral treatment could curb the AIDS epidemic in sub-Saharan Africa

HIV infection and circumcision: cutting through the hyperbole

The objective of this study was to determine whether the justifications given for promoting mass circumcision as a preventive measure for HIV infection are reasonable and whether mass circumcision is a feasible preventive measure for HIV infection in developing countries.

The medical literature concerning the practice of circumcision in the absence of medical indication was reviewed regarding its impact on HIV infection and related issues. The literature was analysed with careful attention to historical perspective.

Our results show that the medical literature supporting mass circumcision for the prevention of HIV infection is inconsistent and based on observation studies. Even if the two ongoing randomised controlled trials in Africa show a protective benefit of circumcision, factors such as the unknown complication rate of the procedure, the permanent injury to the penis, human rights violations and the potential for veiled colonialism need to be taken into account. Based on the best estimates, mass circumcision would not be as cost-effective as other interventions that have been demonstrated to be effective.

Even if effective, mass circumcision as a preventive measure for HIV in developed countries is difficult to justify.

Head to head comparisons in performance of CD4 point-of-care assays: a Bayesian meta-analysis (2000–2013)

Abstract Timely detection, staging, and treatment initiation are pertinent to controlling HIV infection. CD4+ cell-based point-of-care (POC) devices offer the potential to rapidly stage patients, and decide on initiating treatment, but a comparative evaluation of their performance has not yet been performed. With this in mind, we conducted a systematic review and meta-analyses. For the period January 2000 to April 2014, 19 databases were systematically searched, 6619 citations retrieved, and 25 articles selected. Diagnostic performance was compared across devices (i.e., PIMA, CyFlow, miniPOC, MBioCD4 System) and across specimens (i.e., capillary blood vs. venous blood). A Bayesian approach was used to meta-analyze the data. The primary outcome, the Bland–Altman (BA) mean bias (which represents agreement between cell counts from POC device and flow cytometry), was analyzed with a Bayesian hierarchical normal model. We performed a head-to-head comparison of two POC devices including the PIMA and PointCareNOW CD4. PIMA appears to perform better vs. PointCareNOW with venous samples (BA mean bias: –9.5 cells/μL; 95% CrI: –37.71 to 18.27, vs. 139.3 cells/μL; 95% CrI: –0.85 to 267.4, mean difference = 148.8, 95% CrI: 11.8, 285.8); importantly, PIMA performed well when used with capillary samples (BA mean bias: 2.2 cells/μL; 95% CrI: –19.32 to 23.6). Sufficient data were available to allow pooling of sensitivity and specificity data only at the 350 cells/μL cutoff. For PIMA device sensitivity 91.6 (84.7–95.5) and specificity was 94.8 (90.1–97.3), respectively. There were not sufficient data to allow comparisons between any other devices. PIMA device was comparable to flow cytometry. The estimated differences between the CD4+ cell counts of the device and the reference was small and best estimated in capillary blood specimens. As the evidence stands, the PointCareNOW device will need to improve prior to widespread use and more data on MBio and MiniPOC are needed. Findings inform implementation of PIMA and improvements in other CD4 POC device prior to recommending widespread use.

The Day-Hospital of the University Hospital, Bobo Dioulasso: An Example of Optimized HIV Management in Southern Burkina Faso

Objectives

To evaluate the epidemiological evolution of patients with HIV (PtHIV), between 2002 and 2012, in a day-hospital that became an HIV reference centre for south-west Burkina Faso.

Materials and Methods

This was a retrospective study of PtHIV followed in the Bobo Dioulasso university hospital since 2002. The study was based on clinical data recorded using ESOPE software and analysed using Excel and SAS.

Results

A total of 7320 patients have been treated at the centre since 2002; the active file of patients increased from 147 in 2002 to 3684 patients in 2012. Mean age was stable at 38.4 years and the majority were female (71%). The delay to initiation of antiretroviral (ARV) treatment after HIV diagnosis decreased from 12.9 months in 2002 to 7.2 months in 2012. The percentage of PtHIV lost to follow-up, untreated for HIV and deaths all decreased after 2005. Voluntary anonymous screening and/or an evocative clinical picture were the main reasons for HIV diagnosis, usually at a late stage (41.1% at WHO stage 3). Virological success increased due to a decrease in time to initiation of ARV treatment and an increase in percentage of patients treated (90.5% in 2012, mainly with 1^st line drugs). However, there was also a slight increase in the rate of therapeutic failures and the percentage of patients who progressed to 2^nd or 3^rd line-ARVs.

Conclusion

Our day-hospital is a good example of the implementation of a specialist centre for the management of PtHIV in a resource-limited country (Burkina Faso).

Head to head comparisons in performance of CD4 point–of-care assays: A Bayesian meta-analysis (2000-2013)

Background: Timely detection, staging, treatment initiation are pertinent to controlling HIV Infection. CD4+ cell-based point-of-care (POC) devices offer the potential to rapidly stage patients, and decide on initiating treatment, but a comparative evaluation of their performance has not yet been performed. With this in mind, we conducted a systematic review and meta-analyses. Methods: For the period Jan 2000 to April 2015, 19 databases were systematically searched, 6619 citations retrieved, and 25 articles selected. Diagnostic performance was compared across devices (i.e., PIMA, CyFlow, miniPOC, MBioCD4 System) and across specimens (i.e., capillary blood vs. venous blood). A Bayesian approach was used to meta-analyze the data. The primary outcome, the Bland-Altman (BA) mean bias (which represents agreement between cell counts from POC device and flow cytometry), was analyzed with a Bayesian hierarchical normal model. Findings: We performed a head-to-head comparison of two point-of-care devices, PIMA and PointCareNOW CD4. PIMA appears to perform better vs. PointCareNOW with venous samples (BA mean bias: -9.5 cells/μL; 95% CrI:-37.71 to 18.27 vs. 139.3 cells/μL; 95% CrI:-0.85 to 267.4, mean difference = 148.8, 95% CrI: 11.8, 285.8); however, PIMA’s best performed when used with capillary samples (BA mean bias: 2.2 cells/μL; 95% CrI:-19.32 to 23.6). Sufficient data was available to allow pooling of sensitivity and specificity data only at the 350 cells/μL cutoff. For PIMA device sensitivity 91.6 (84.7 to 95.5) and specificity was 94.8 (90.1 to 97.3) respectively. There was not sufficient data to allow comparisons between any other devices. Conclusions: PIMA device was comparable to flow cytometry. The estimated differences between the CD4+ cell counts of the device and the reference was small and best estimated in capillary blood specimens. As the evidence stands, the PointCareNOW device will need to improve prior to widespread use and more data on MBio and MiniPOC are needed. Findings inform implementation of PIMA and improvements in other CD4 POC device prior to recommending widespread use.

The 2013 WHO guidelines for antiretroviral therapy: evidence-based recommendations to face new epidemic realities

PURPOSE OF REVIEW

The review summarizes the key new recommendations of the WHO 2013 guidelines for antiretroviral therapy and describes the potential impact of these recommendations on the HIV epidemic.

RECENT FINDINGS

The 2013 WHO guidelines recommend earlier initiation of antiretroviral therapy (ART) at CD4 500 cells/μl or less for all adults and children above 5 years. Further recommendations include initiation of ART irrespective of CD4 cell count or clinical stage for people co-infected with active tuberculosis disease or hepatitis B virus with severe liver disease, pregnant women, people in serodiscordant partnerships, and children under 5 years of age. The ART regimen comprising a once daily fixed-dose combination of tenofovir + lamivudine (or emtricitabine) + efavirenz is recommended as the preferred first-line therapy. Several approaches are also recommended to reach more people and increase health service capacity, including community and self-testing, and task shifting, decentralization, and integration of ART care.

SUMMARY

If fully implemented, the 2013 WHO ART guidelines could avert at least an additional 3 million deaths and prevent close to an additional 3.5 million new infections between 2012 and 2025 in low- and middle-income countries, compared with previous treatment guidelines.

Mortality in women of reproductive age in rural South Africa

OBJECTIVE

To determine causes of death and associated risk factors in women of reproductive age in rural South Africa.

METHODS

Deaths and person-years of observation (pyo) were determined for females (aged 15-49 years) resident in 15,526 households in a rural South African Demographic and Health Surveillance site from 2000 to 2009. Cause of death was ascertained by verbal autopsy and ICD-10 coded; causes were categorized as HIV/TB, non-communicable, communicable/maternal/perinatal/nutrition, injuries, and undetermined (unknown). Characteristics of women were obtained from regularly updated household visits, while HIV and self-reported health status was obtained from the annual HIV surveillance. Overall and cause-specific mortality rates (MRs) with 95% confidence intervals (CI) were calculated. The Weibull regression model (HR, 95%CI) was used to determine risk factors associated with mortality.

RESULTS

A total of 42,703 eligible women were included; 3,098 deaths were reported for 212,607 pyo. Overall MRwas 14.6 deaths/1,000 pyo (95% CI: 14.1-15.1), peaking in 2003 (MR 18.2/1,000 pyo, 95% CI: 16.4-20.1) and declining thereafter (2009: MR 9.6/1,000 pyo, 95% CI: 8.410.9). Mortality was highest for HIV/TB (MR 10.6/1,000 pyo, 95% CI: 10.211.1), accounting for 73.1% of all deaths, ranging from 61.2% in 2009 to 82.7% in 2002. Adjusting for education level, marital status, age, employment status, area of residence, and migration, all-cause mortality was associated with external migration (adjusted hazard ratio, or aHR), 1.70, 95% CI: 1.41-2.05), self-reported poor health status (aHR 8.26, 95% CI: 2.94-23.15), and HIV-infection (aHR 7.84, 95% CI: 6.26-9.82); external migration and HIV infection were also associated with causes of mortality other than HIV/TB (aHR 1.62 CI: 1.12-2.34 and aHR 2.59, CI: 1.79-3.75).

CONCLUSION

HIV/TB was the leading cause of death among women of reproductive age, although rates declined with the rollout of HIV treatment in the area from 2004. Women's age, external migration status, and HIV-positive status were significantly associated with all-cause and cause-specific mortality.

Change in sexual activity 12 months after ART initiation among HIV-positive Mozambicans

We assessed sexual behaviors before and 12-months after ART initiation among 277 Mozambicans attending an HIV clinic. Measured behaviors included the number of sexual partners, condom use, concurrent relationships, disclosure of HIV status, alcohol use, and partners' serostatus. Compared to before ART initiation, increases were seen 12 months after ART in the proportion of participants who were sexually active (48% vs. 64% respondents, P < 0.001) and the proportion of participants with HIV-negative or unknown serostatus partners (45% vs. 80%, P < 0.001). Almost all (96%) concurrent partnerships reported at 12 months formed after ART initiation. Although reported correct and consist condom use increased, the number of unprotected sexual relationships remained the same (n = 45). Non-disclosure of HIV-serostatus to sexual partners was the only significant predictor of practicing unprotected sex with partners of HIV-negative or unknown serostatus. Sexual activity among HIV-positive persons on ART increased 12 months after ART initiation. Ongoing secondary transmission prevention programs addressing sexual activity with multiple partners, disclosure to partners and consistent condom use with serodisconcordant partners must be incorporated throughout HIV care programs.

The cost-effectiveness of preventing mother-to-child transmission of HIV in low- and middle-income countries: systematic review

BACKGROUND

Although highly effective prevention interventions exist, the epidemic of paediatric HIV continues to challenge control efforts in resource-limited settings. We reviewed the cost-effectiveness of interventions to prevent mother-to-child transmission (MTCT) of HIV in low- and middle-income countries (LMICs). This article presents syntheses of evidence on the costs, effects and cost-effectiveness of HIV MTCT strategies for LMICs from the published literature and evaluates their implications for policy and future research.

METHODS

Candidate studies were identified through a comprehensive database search including PubMed, Embase, Cochrane Library, and EconLit restricted by language (English or French), date (January 1st, 1994 to January 17th, 2011) and article type (original research). Articles reporting full economic evaluations of interventions to prevent or reduce HIV MTCT were eligible for inclusion. We searched article bibliographies to identify additional studies. Two authors independently assessed eligibility and extracted data from studies retained for review. Study quality was appraised using a modified BMJ checklist for economic evaluations. Data were synthesised in narrative form.

RESULTS

We identified 19 articles published in 9 journals from 1996 to 2010, 16 concerning sub-Saharan Africa. Collectively, the articles suggest that interventions to prevent paediatric infections are cost-effective in a variety of LMIC settings as measured against accepted international benchmarks. In concentrated epidemics where HIV prevalence in the general population is very low, MTCT strategies based on universal testing of pregnant women may not compare well against cost-effectiveness benchmarks, or may satisfy formal criteria for cost-effectiveness but offer a low relative value as compared to competing interventions to improve population health.

CONCLUSIONS AND RECOMMENDATIONS

Interventions to prevent HIV MTCT are compelling on economic grounds in many resource-limited settings and should remain at the forefront of global HIV prevention efforts. Future cost-effectiveness analyses can help to ensure that pMTCT interventions for LMICs reach their full potential by focussing on unanswered questions in four areas: local assessment of rapidly evolving HIV MTCT options; strategies to improve coverage and reach underserved populations; evaluation of a more comprehensive set of MTCT approaches including primary HIV prevention and reproductive counselling; integration of HIV MTCT and other sexual and reproductive health services.

Preventing mother to child transmission of HIV with highly active antiretroviral treatment in Tanzania--a prospective cost-effectiveness study

Recent guidelines recommend that all HIV-infected women should receive highly active antiretroviral therapy throughout pregnancy and lactation, irrespective of whether or not they need it for their own health. This strategy for prevention of mother to child transmission (PMTCT) of HIV is more effective than the well-established use of single-dose nevirapine, but it is also a more costly alternative. In this economic evaluation, we use a decision model to combine the best available clinical evidence with cost, epidemiological and behavioral data from Northern Tanzania. We find that a highly active antiretroviral therapy-based PMTCT Plus regimen is more cost effective than the current Tanzanian standard of care with single-dose nevirapine. Although PMTCT Plus is roughly 40% more expensive per pregnant woman than single-dose nevirapine, the expected health benefits are 5.2 times greater. The incremental cost effectiveness ratio of the PMTCT Plus intervention is calculated to be 4062 USD per child infection averted and 162 USD per disability adjusted life year.

Association of highly active antiretroviral therapy coverage, population viral load, and yearly new HIV diagnoses in British Columbia, Canada: a population-based study

BACKGROUND

Results of cohort studies and mathematical models have suggested that increased coverage with highly active antiretroviral therapy (HAART) could reduce HIV transmission. We aimed to estimate the association between plasma HIV-1 viral load, HAART coverage, and number of new cases of HIV in the population of a Canadian province.

METHODS

We undertook a population-based study of HAART coverage and HIV transmission in British Columbia, Canada. Data for number of HIV tests done and new HIV diagnoses were obtained from the British Columbia Centre for Disease Control. Data for viral load, CD4 cell count, and HAART use were extracted from the British Columbia Centre for Excellence in HIV/AIDS population-based registries. We modelled trends of new HIV-positive tests and number of individuals on HAART using generalised additive models. Poisson log-linear regression models were used to estimate the association between new HIV diagnoses and viral load, year, and number of individuals on HAART.

FINDINGS

Between 1996 and 2009, the number of individuals actively receiving HAART increased from 837 to 5413 (547% increase; p=0.002), and the number of new HIV diagnoses fell from 702 to 338 per year (52% decrease; p=0.001). The overall correlation between number of individuals on HAART and number of individuals newly testing positive for HIV per year was -0.89 (p<0.0001). For every 100 additional individuals on HAART, the number of new HIV cases decreased by a factor of 0.97 (95% CI 0.96-0.98), and per 1 log(10) decrease in viral load, the number of new HIV cases decreased by a factor of 0.86 (0.75-0.98).

INTERPRETATION

We have shown a strong population-level association between increasing HAART coverage, decreased viral load, and decreased number of new HIV diagnoses per year. Our results support the proposed secondary benefit of HAART used within existing medical guidelines to reduce HIV transmission.

FUNDING

Ministry of Health Services and Ministry of Healthy Living and Sport, Province of British Columbia; US National Institute on Drug Abuse; US National Institutes of Health; Canadian Institutes of Health Research.

The past, present and future of HIV, AIDS and resource allocation

Background

How should HIV and AIDS resources be allocated to achieve the greatest possible impact? This paper begins with a theoretical discussion of this issue, describing the key elements of an "evidence-based allocation strategy". While it is noted that the quality of epidemiological and economic data remains inadequate to define such an optimal strategy, there do exist tools and research which can lead countries in a way that they can make allocation decisions. Furthermore, there are clear indications that most countries are not allocating their HIV and AIDS resources in a way which is likely to achieve the greatest possible impact. For example, it is noted that neighboring countries, even when they have a similar prevalence of HIV, nonetheless often allocate their resources in radically different ways.

These differing allocation patterns appear to be attributable to a number of different issues, including a lack of data, contradictory results in existing data, a need for overemphasizing a multisectoral response, a lack of political will, a general inefficiency in the use of resources when they do get allocated, poor planning and a lack of control over the way resources get allocated.

Methods

There are a number of tools currently available which can improve the resource-allocation process. Tools such as the Resource Needs Model (RNM) can provide policymakers with a clearer idea of resource requirements, whereas other tools such as Goals and the Allocation by Cost-Effectiveness (ABCE) models can provide countries with a clearer vision of how they might reallocate funds.

Results

Examples from nine different countries provide information about how policymakers are trying to make their resource-allocation strategies more "evidence based". By identifying the challenges and successes of these nine countries in making more informed allocation decisions, it is hoped that future resource-allocation decisions for all countries can be improved.

Conclusion

We discuss the future of resource allocation, noting the types of additional data which will be required and the improvements in existing tools which could be made.

The impact of HIV treatment on risk behaviour in developing countries: A systematic review

In developing countries, access to antiretroviral therapy (ART) is improving as HIV treatment becomes a greater priority in the global fight against AIDS. While ART has clearly beneficial clinical effects, increased access to treatment may also affect sexual behaviour. To examine the strength of evidence for the impact of medical treatment for HIV-positive individuals on behavioural outcomes in developing countries, we conducted a comprehensive search of the peer-reviewed literature. Studies were included if they provided clinical treatment to HIV-positive individuals in a developing country, compared behavioural, psychological, social, care, or biological outcomes related to HIV-prevention using a pre/post or multi-arm study design, and were published between January 1990 and January 2006. Only three studies were identified that met the inclusion criteria. All were conducted in Africa, utilized before/after or multi-arm study designs, and relied on self-reported behaviour. In all three studies, a majority of HIV-infected individuals reported being sexually abstinent, and access to ART was not associated with an increase in HIV-related risky sexual behaviours. However, one cross-sectional study found that ART patients were more likely to report STD treatment. The available evidence indicates a significant reduction in risk behaviour associated with ART in developing countries. However, there are few existing studies and the rigor of these studies is weak. More studies are needed to build an evidence base on which to make programmatic and policy decisions.

Initiation of antiretroviral therapy leads to a rapid decline in cervical and vaginal HIV-1 shedding

BACKGROUND

Antiretroviral therapy (ART) may decrease HIV-1 infectivity in women by reducing genital HIV-1 shedding.

OBJECTIVES

To evaluate the time course and magnitude of decay in cervical and vaginal HIV-1 shedding as women initiate ART.

METHODS

This prospective, observational study of 20 antiretroviral-naive women initiating ART with stavudine, lamivudine, and nevirapine measured HIV-1 RNA in plasma, cervical secretions, and vaginal secretions. Qualitative polymerase chain reaction estimated HIV-1 DNA in cervical and vaginal samples. Perelson's two-phase viral decay model and non-linear random effects were used to compare RNA decay rates. Decreases in proviral DNA were evaluated using logistic regression and generalized estimating equations.

RESULTS

Significant decreases in the quantity of HIV-1 RNA were observed by day 2 in plasma (P < 0.001), day 2 in cervical secretions (P = 0.001), and day 4 in vaginal secretions (P < 0.001). Modeled initial and subsequent RNA decay rates in plasma, cervical secretions, and vaginal secretions were 0.6, 0.8, and 1.2 log10 virions/day, and 0.04, 0.05, and 0.06 log10 virions/day, respectively. The initial decay rate for vaginal HIV-1 RNA was more rapid than for plasma RNA (P = 0.02). Detection of HIV-1 DNA decreased significantly in vaginal secretions during the first week (P < 0.001). At day 28, 10 women had detectable HIV-1 RNA or proviral DNA in genital secretions.

CONCLUSIONS

Genital HIV-1 shedding decreased rapidly after ART initiation, consistent with a rapid decrease in infectivity. However, incomplete viral suppression in half of these women may indicate an ongoing risk of transmission.

Are targeted HIV prevention activities cost-effective in high prevalence settings? Results from a sexually transmitted infection treatment project for sex workers in Johannesburg, South Africa

OBJECTIVE

The objective of this study was to estimate the cost-effectiveness of syndromic management, with and without periodic presumptive treatment (PPT), in averting sexually transmitted infections (STIs) and HIV in female sex workers (FSWs) participating in a hotel-based intervention in Johannesburg.

STUDY DESIGN

Financial and economic providers' costs were estimated. A mathematical model, fitted to epidemiologic data, projected the HIV and STIs averted by the intervention. Cost per HIV infection and DALY averted were estimated for different general population HIV prevalences.

RESULTS

Projections suggest 53 HIV infections were averted (July 2000-June 2001) and a 3.1% decrease in the FSW HIV incidence. Cost-effectiveness was US dollars 78 per DALY averted. Incremental cost of PPT was US dollars 31 per disability-adjusted life year (DALY) averted. Initiating the intervention at 15% general HIV prevalence would have improved cost-effectiveness by 35%. Expanding PPT coverage to mass-treat all FSWs (instead of <17%) and their clients could increase impact 14-fold.

CONCLUSION

The results highlight targeted interventions can be cost-effective at all stages of HIV epidemics and suggests PPT could improve the cost-effectiveness of targeted STI interventions.

Effectiveness and cost effectiveness of early and late prevention of HIV/AIDS progression with antiretrovirals or antibiotics in Southern African adults

As HIV/AIDS drugs are becoming more widely available in Southern Africa, we compared the effectiveness and cost effectiveness of different treatment options, using a Markov Monte Carlo simulation model based on published estimates of disease progression, treatment effectiveness and health care costs. Cost and outcome values were discounted. Quality of life was considered. Acceptability curves summarized uncertainties. Sensitivity analyses tested assumptions. Results showed that triple antiretroviral therapy (ARV) plus antibiotics would prolong life by 6.7 undiscounted years if provided 'late' (CD4 = 200 cells/microl) and by 9.8 years if provided 'early' (CD4 = 350 cells/microl). The incremental undiscounted costs per year of life gained, compared to no preventive therapy, were $17 for isoniazid plus cotrimoxazole started late, $244 for both antibiotics started early, $2454 for ARV plus antibiotics started late and $2784 for ARV plus both antibiotics started early. The discounted incremental costs per quality adjusted life year (QALY) gained were, respectively, $29 saving, $254, $4937 and $3057. Late ARV plus both antibiotics was the strategy most likely to be cost effective if society was willing to pay more than $2000 per life year gained. Cost-effectiveness estimates were sensitive to discounting and assumed treatment costs but were less sensitive to assumed treatment effectiveness.

Early initiation of highly active antiretroviral therapies for AIDS: dynamic choice with endogenous and exogenous learning

Criteria for initiation of highly active antiretroviral treatments (HAART) in HIV-infected patients remain a matter of debate world-wide because short-term benefits have to be balanced with costs of these therapies, and restrictions placed on future treatment options if resistant viral strains develop. On the other hand, postponing the introduction of HAART may involve a therapeutic opportunity cost if a patient's health is allowed to deteriorate to such an extent of becoming unable to benefit from new treatments currently under development when they become available. We introduce a two period model where period one treatment adoption is an irreversible act with future, but uncertain, consequences. New information, both endogenous and exogenous, arises over time and shapes the conditions surrounding the second period therapeutic decision. A surprising result is that, under conditions that appear close to those surrounding the HAART debate, the magnitude of the feared resistance effect has no effect on leaves the optimal treatment decision as far as it is high enough.

Is antiretroviral therapy cost-effective in South Africa?

Braithwaite and Tsevat discuss a new study that suggests that antiretroviral treatment is indeed cost-effective.

The epidemiological impact of antiretroviral use predicted by mathematical models: a review

This review summarises theoretical studies attempting to assess the population impact of antiretroviral therapy (ART) use on mortality and HIV incidence. We describe the key parameters that determine the impact of therapy, and argue that mathematical models of disease transmission are the natural framework within which to explore the interaction between antiviral use and the dynamics of an HIV epidemic. Our review focuses on the potential effects of ART in resource-poor settings. We discuss choice of model type and structure, the potential for risk behaviour change following widespread introduction of ART, the importance of the stage of HIV infection at which treatment is initiated, and the potential for spread of drug resistance. These issues are illustrated with results from models of HIV transmission. We demonstrate that HIV transmission models predicting the impact of ART use should incorporate a realistic progression through stages of HIV infection in order to capture the effect of the timing of treatment initiation on disease spread. The realism of existing models falls short of properly reproducing patterns of diagnosis timing, incorporating heterogeneity in sexual behaviour, and describing the evolution and transmission of drug resistance. The uncertainty surrounding certain effects of ART, such as changes in sexual behaviour and transmission of ART-resistant HIV strains, demands exploration of best and worst case scenarios in modelling, but this must be complemented by surveillance and behavioural surveys to quantify such effects in settings where ART is implemented.

When to initiate antiretroviral therapy in HIV-1-infected adults: a review for clinicians and patients

One of the most controversial topics in the medical management of HIV disease is the optimal time to initiate highly active antiretroviral therapy (HAART) in HIV-1-infected adults. Premature exposure to antiretrovirals may precipitate early evolution of resistance and unnecessary side-effects, whereas remaining off HAART until late in the course of HIV disease may lead to reduced therapeutic benefits and elevated mortality. The lack of a randomised clinical trial to consider this issue has resulted in ongoing revision of expert recommendations and substantial variability between international consensus guidelines regarding the optimal time to initiate therapy. Since this uncertainty is a source of unease for both patients and clinicians, we summarise the latest evidence regarding the optimal time to initiate HAART with consideration of the potential benefits and drawbacks of starting HIV treatment at the different levels presently recommended in leading consensus guidelines.

The cost of inaction on HIV transmission among injection drug users and the potential for effective interventions

Estimated and potential medical costs of treating patients infected with human immunodeficiency virus (HIV) in urban areas of high HIV prevalence have not been well defined. We estimated the total medical cost of HIV disease among injection drug users in Vancouver, British Columbia, Canada, assuming stable and increasing HIV prevalence. Total medical costs were estimated by multiplying the average lifetime medical cost per person by the number of HIV-infected individuals. We assumed the cost of each HIV infection to be 150,000 Canadian dollars, based on empirical data, and HIV prevalence estimates were derived from the Vancouver Injection Drug Users Study (VIDUS) and external data sources. By use of Monte Carlo simulation methodology, we performed sensitivity analyses to estimate total medical cost, assuming the HIV prevalence remained stable at 31% and under a scenario in which the prevalence rose to 50%. Expected medical expenditures based on current HIV prevalence levels were estimated as 215,852,613 Canadian dollars. If prevalence rises to 50% as reported in other urban centers, the median estimated medical cost would be approximately 348,935,865 Canadian dollars. This represents a difference in the total costs between the two scenarios of 133,083,253 Canadian dollars. Health planners should consider that predicted medical expenditures related to the HIV epidemic among injection drug users in our setting may cost an estimated 215,852,613 Canadian dollars. If funding cannot be found for appropriate prevention interventions and the prevalence rises to 50%, a further 133,083,253 Canadian dollars may be required.

Human immunodeficiency virus type 1 infection in Oman: antiretroviral therapy and frequencies of drug resistance mutations

Highly active antiretroviral therapy (HAART), consisting mainly of two nucleoside reverse transcriptase inhibitors (NRTIs) and one protease inhibitor (PI), is offered to < 10% of HIV-infected subjects in Oman. The aims of the present study were to determine the frequency of resistance-associated mutations in these patients, and to assess the contribution of drug resistance to treatment outcome. Among 29 patients on HAART for > or =6 months, virological, failure was observed in 27 (93%). Genotypic analysis indicated that in five of these 27 patients, there were no mutations that confer resistance to reverse transcriptase inhibitors (RTIs). The genotypes of 17 other patients carried one or two RTI mutations, mainly the lamivudine-associated resistance mutation M184V. Three or more RTI mutations were found in only five (14.7%) patients with virological failure, including three patients on the nonnucleoside RTI efavirenz. Major PI mutations were infrequent, and were detected in seven (26%) of 27 patients failing HAART, mainly as single mutation at codons 82 or 90. In contrast, accessory mutations in the protease gene were present in all patients. However, there were significant differences in the prevalence of accessory mutations at codons 36 and 77 among clade B and non-B viruses. When genotypic data of this study were used to change therapy of seven patients whose isolates had multiple resistance mutations, adequate viral suppression was observed in five. Our results indicate that the high rate of treatment failure among patients in Oman is mainly due to factors other than resistance to antiretroviral drugs. These factors, which may include nonadherence to therapy and treatment interruptions, need to be investigated.

Can highly active antiretroviral therapy reduce the spread of HIV?: A study in a township of South Africa

BACKGROUND

Calls have been made for the large-scale delivery of highly active antiretroviral therapy (HAART) to people infected with HIV in developing countries. If this is to be done, estimates of the number of people who currently require HAART in high HIV prevalence areas of sub-Saharan Africa are needed, and the impact of the widespread use of HAART on the transmission and, hence, spread of HIV must be assessed.

OBJECTIVES

To estimate the proportion of people eligible for combination antiretroviral therapy and to evaluate the potential impact of providing HAART on the spread of HIV-1 under World Health Organization (WHO) guidelines in a South African township with a high prevalence of HIV-1.

DESIGN

A community-based cross-sectional study in a township near Johannesburg, South Africa, of a random sample of approximately 1000 men and women aged 15 to 49 years.

METHODS

Background characteristics and sexual behavior were recorded by questionnaire. Participants were tested for HIV-1, and their CD4 cell counts and plasma HIV-1 RNA loads were measured. The proportion of people whose CD4 cell count was less than 200 cells/mm and who would be eligible to receive HAART under WHO guidelines was estimated. The potential impact of antiretroviral drugs on the spread of HIV-1 in this setting was determined by estimating among the partnerships engaged in by HIV-1-positive individuals the proportion of spousal and nonspousal partnerships eligible to receive HAART and then by calculating the potential impact of HAART on the annual risk of HIV-1 transmission due to sexual contacts with HIV-1-infected persons. The results were compared with those obtained using United States Department of Health and Human Services (USDHHS) guidelines.

RESULTS

The overall prevalence of HIV-1 infection was 21.8% (19.2%-24.6%), and of these people, 9.5% (6.1%-14.9%) or 2.1% (1.3%-3.3%) of all those aged 15 to 49 years would be eligible for HAART (ranges are 95% confidence limits). In each of the next 3 years 6.3% (4.6%-8.4%) of those currently infected with HIV-1 need to start HAART. Among the partnerships in which individuals were HIV-1-positive, only a small proportion of spousal partnerships (7.6% [3.4%-15.6%]) and nonspousal partnerships (5.7%, [3.0%-10.2%]) involved a partner with a CD4 cell count below 200 cells/mm and would have benefited from the reduction of transmission due to the decrease in plasma HIV-1 RNA load under HAART. Estimates of the impact of HAART on the annual risk of HIV-1 transmission show that this risk would be reduced by 11.9% (7.1%-17.0%). When using USDHHS guidelines, the proportion of HIV-1-positive individuals eligible for HAART reached 56.3% (49.1%-63.2%) and the impact of HAART on the annual risk of HIV-1 transmission reached 71.8% (64.5%-77.5%).

CONCLUSIONS

The population impact of HAART on reducing sexual transmission of HIV-1 is likely to be small under WHO guidelines, and reducing the spread of HIV-1 will depend on further strengthening of conventional prevention efforts. A much higher impact of HAART is to be expected if USDHHS guidelines are used.

A review of studies assessing the costs and consequences of interventions to reduce mother-to-child HIV transmission in sub-Saharan Africa

OBJECTIVE

To review the methods and findings of studies that assess the costs and consequences of interventions to reduce mother-to-child HIV transmission in sub-Saharan Africa.

DESIGN

Systematic literature review.

METHODS

A literature search was conducted to identify studies that assessed the costs and consequences of interventions aimed at reducing mother-to-child HIV transmission in African populations. The methodological quality of included studies was appraised using the British Medical Journal Economic Evaluation Working Party checklist and data were extracted for comparison using a data extraction template.

RESULTS

Nine studies, all of which used modelling techniques to predict the cost-effectiveness of anti-retroviral interventions, were identified for inclusion in the review. The quality of reporting was found to be lacking in several key areas. In particular a lack of detail was given regarding quantities of resources required for interventions, and the methods for valuing health outcomes and unit costs. In general, the more recent evaluations report more favourable cost-effectiveness ratios than earlier studies due to lower drug costs and in some cases the use of shorter drug regimens.

CONCLUSIONS

Comparisons between studies were hampered by variations in the values attached to model parameters and by differences in the structure and design of models. The most encouraging findings have been reported for the CDC short zidovudine regimen and the HIVNET012 single dose nevirapine regimen. The generalizability of these findings is limited by the use of incremental costing, combined with uncertainty surrounding the level of infrastructure required to implement the interventions. In low-income sub-Saharan countries, the costs of strengthening the infrastructure to levels capable of providing such interventions, needs to be assessed before an optimal policy for the prevention of mother-to-child HIV transmission in sub-Saharan Africa can be established.

Racial distribution of Candida dubliniensis colonization among South Africans

Candida dubliniensis is a yeast species that has only recently been differentiated from Candida albicans. C. dubliniensis colonization was initially associated with human immunodeficiency virus (HIV)-positive individuals. Because of the large proportion of AIDS patients in South Africa, we tested the generality of this association by assessing the prevalence of C. dubliniensis colonization among 253 black HIV-positive individuals, 66 healthy black individuals, 22 white HIV-positive individuals, and 55 healthy white individuals in South Africa carrying germ tube-positive yeasts in their oral cavities. Molecular fingerprinting with Ca3, a complex DNA fingerprinting probe specific for C. albicans, and Cd25, a complex DNA fingerprinting probe specific for C. dubliniensis, provides the first conclusive evidence of the existence of C. dubliniensis among South African clinical yeast isolates and reveals a higher relative prevalence of this species among white healthy individuals (16%) than among HIV-positive white individuals (9%), black healthy individuals (0%), and black HIV-positive individuals (1.5%). A cluster analysis separated South African C. dubliniensis isolates into two previously described groups, groups I and II, with the majority of isolates clustering in group I. Isolates from white healthy individuals exhibited a higher level of relatedness. A comparison of the C. dubliniensis isolates from South Africa with a general collection of C. dubliniensis isolates collected worldwide revealed no South Africa-specific clade, as has been demonstrated for C. albicans. These results suggest that in South Africa, C. dubliniensis carriage is influenced more by race than by HIV infection status.

AIDS and antiretroviral drugs in South Africa: public health, politics, and individual suffering: a review of Brian Tilley's It's my life

The word “epidemic” seems inadequate to describe the spread of the HIV virus in sub-Saharan Africa. The latest estimates suggest that 28.5 million people in this region are infected, including 5 million in South Africa alone. The HIV and AIDS pandemic, with infection rates of over 20 percent in seven African countries, rivals the worst of history's disease outbreaks, including the bubonic plague of medieval times. The devastating effects of the disease on the continent are compounded by extreme poverty in the region and the lack of medical infrastructure essential for delivering the full range of available treatments for HIV infection, AIDS, and the opportunistic infections associated with the disease. Of the 40 million people infected with HIV worldwide, only 730,000 receive combination antiretroviral therapies. In the entire African continent, only 30,000 infected people currently receive such forms of treatment.

Socioeconomic status, access to triple therapy, and survival from HIV-disease since 1996

BACKGROUND

In the era before highly active antiretroviral therapy (HAART), socioeconomic status was associated with survival from HIV disease. We have explored socioeconomic status, access to triple therapy (HAART), and mortality in the context of a universal healthcare system.

METHODS

We evaluated 1408 individuals who initiated double or triple therapy between 1 August 1996 and 31 December 1999, and were followed until 31 March 2000. Cumulative HIV-related mortality rates were estimated using Kaplan-Meier methods and Cox proportional hazards regression.

RESULTS

In the overall Cox model, we found that adherence [risk ratio (RR) 0.83; per 10% increase], CD4 cell count (RR 1.53; per 100 cell decrease), and lower socioeconomic status (RR 2.19; high versus low), were associated with HIV-related mortality. However, socioeconomic status was not significant among patients prescribed triple therapy in a stratified analysis, or in a sub-analysis restricted to patients prescribed HAART in the initial regimen. When we investigated if inequitable access to HAART by socio-economic status could explain the discrepancy, we found that persons in the lower socio-economic strata were less likely to be prescribed triple therapy even after adjustment for clinical characteristics.

CONCLUSION

In a universal healthcare system, socioeconomic status was strongly associated with HIV-related mortality. When we investigated possible explanations for this association, we found that individuals of lower socioeconomic status were less likely to receive triple therapy after adjustment for clinical characteristics. Our findings highlight the need for the monitoring of therapeutic guidelines to ensure equitable access, as treatment strategies are updated.

Antifungal susceptibility of South African oral yeast isolates from HIV/AIDS patients and healthy individuals

The in vitro antifungal susceptibility profile of 589 oral yeast isolates from HIV/AIDS patients and healthy South Africans was determined against amphotericin B, nystatin, 5-fluorocytosine (5-FC), clotrimazole, miconazole, ketoconazole, itraconazole and fluconazole. The broth microdilution method of the National Committee on Clinical Laboratory Standards was used and MIC(50) and MIC(90) determined. A 100% susceptibility to fluconazole was observed among the 466 isolates of Candida albicans. Among C. krusei, the second most common isolate, only 2.6% of isolates were susceptible to fluconazole and itraconazole. Despite the lack of previous exposure to antifungal agents, very little difference was observed in the antifungal profile between the South African isolates and isolates from the United States (U.S.), Canada and South America. South Africa has a particularly high incidence of HIV-infection and oral candidiasis is the most common oral complication in these patients. This study provides important baseline data as the isolates were collected prior to fluconazole being made freely available to HIV/AIDS patients attending government health clinics.

Potential benefit and limitations of a broad access to potent antiretroviral therapy in developing countries

In industrialised countries, highly active antiretroviral therapy (HAART) has drastically reduced HIV mortality. Only few developing countries have introduced HAART on a large scale, leaving millions of HIV-infected individuals without life-saving therapy. Although HAART appears to be economically viable for middle income countries, it remains unaffordable for many of the poorest and worst affected nations. In response, significant discounts for antiretrovirals and debt relief have been granted. Apart from economic problems, other important issues need to be addressed before antiretroviral therapy can be optimally utilised, including the logistics of drug supply, HIV education for hospital staff and patients, and laboratory facilities that allow clinicians to assess the efficacy of HAART.

Cost-effectiveness of HIV/AIDS interventions in Africa: a systematic review of the evidence

BACKGROUND

Evidence for cost-effectiveness of interventions for HIV/AIDS in Africa is fragmentary. Cost-effectiveness is, however, highly relevant. African governments face difficult choices in striking the right balance between prevention, treatment, and care, all of which are necessary to deal comprehensively with the epidemic. Reductions in drug prices have raised the priority of treatment, though treatment access is restricted. We assessed the existing cost-effectiveness data and its implications for value-for-money strategies to combat HIV/AIDS in Africa.

METHODS

We undertook a systematic review using databases and consultations with experts. We identified over 60 reports that measured both the cost and effectiveness of HIV/AIDS interventions in Africa. 24 studies met our inclusion criteria and were used to calculate standardised estimates of the cost (US$ for year 2000) per HIV infection prevented and per disability-adjusted life-year (DALY) gained for 31 interventions.

FINDINGS

Cost-effectiveness varied greatly between interventions. A case of HIV/AIDS can be prevented for $11, and a DALY gained for $1, by selective blood safety measures, and by targeted condom distribution with treatment of sexually transmitted diseases. Single-dose nevirapine and short-course zidovudine for prevention of mother-to-child transmission, voluntary counselling and testing, and tuberculosis treatment, cost under $75 per DALY gained. Other interventions, such as formula feeding for infants, home care programmes, and antiretroviral therapy for adults, cost several thousand dollars per infection prevented, or several hundreds of dollars per DALY gained.

INTERPRETATION

A strong economic case exists for prioritisation of preventive interventions and tuberculosis treatment. Where potentially exclusive alternatives exist, cost-effectiveness analysis points to an intervention that offers the best value for money. Cost-effectiveness analysis is an essential component of informed debate about priority setting for HIV/AIDS.

Overcoming challenges to the implementation of antiretroviral therapy in Kenya

Dramatic price reductions make antiretroviral drugs increasingly affordable in Africa. However, poor infrastructure, conflicting interests, and lack of commitment to a common strategy could keep them beyond the reach of most infected people. Recent experiences in Kenya, where the political will exists, show the complexity of turning this opportunity into safe and effective practice.

HIV/AIDS care in KwaZulu-Natal, South Africa: an interview with Dr. Leana Uys. Interviewed by Ellen Giarelli and Linda A. Jacobs

Human suffering from the HIV/AIDS epidemic in Africa has reached unprecedented proportions. In 1998, an estimated 50% of all new infections in sub-Saharan Africa occurred in South Africa; and it is predicted that by the year 2003, South Africa will be experiencing a negative population growth. Besides the toll in human lives, the estimated cost for basic care and prevention services in Africa is 10 times the current expenditure. Three unique factors are critical in the South African HIV/AIDS epidemic: HIV transmission patterns, the effect of this disease on women and children, and the role that traditional healers play in the treatment of HIV/AIDS. In a recent interview, Dr. Leana Uys, an educational leader in the School of Nursing at the University of Natal in Durban, Republic of South Africa, provided an insightful perspective on HIV/AIDS policies and related sociocultural issues that have a direct effect on the HIV/AIDS epidemic. She communicated her personal experiences as well as the experiences of South African nurses working as caregivers, educators, and policy makers with AIDS patients and their families in KwaZulu-Natal.

Preventing antiretroviral anarchy in sub-Saharan Africa

Combination antiretroviral therapy has dramatically improved the survival of patients living with HIV and AIDS in industrialised countries of the world. Despite this enormous benefit, there are some major problems and obstacles to be overcome.(1) Treatment of HIV-infection is likely to be lifelong.(2) Unfortunately, many HIV-infected individuals cannot tolerate the toxic effects of the drugs, or have difficulty complying with treatment which involves large numbers of pills and complicated dosing schedules. Poor adherence to treatment leads to the emergence of drug-resistant viral strains that need new combinations of drugs or new drugs altogether.

The global epidemiology of HIV/AIDS

In this paper, the ways in which HIV is transmitted and factors facilitating transmission are described, although we still do not fully understand why the HIV epidemic has spread so heterogeneously across the globe. Estimates of HIV prevalence vary in quality but give some idea of trends in different countries and regions. Of all regions in the world, sub-Saharan Africa is the hardest hit by HIV, containing around 70% of people living with HIV/AIDS. There are, however, recent signs of hope in Africa due to a slight reduction in the number of new HIV cases in the year 2000. Most countries in Asia have not seen explosive epidemics in the general population up to now but patterns of injecting drug use (IDU) and sex work are conducive to the spread of HIV so there is no room for complacency. Unpredictable epidemics among IDU in the former Soviet Union have the potential to spread into the general population. Some countries in Central America and the Caribbean have growing HIV epidemics with adult prevalences second only to sub-Saharan Africa. Reductions in morbidity and mortality through the use of highly active antiretroviral therapy are at present limited to high-income and some Latin American countries. Both the cost of these therapies and the poor health care delivery systems in many affected countries need to be addressed before antiretrovirals can benefit the majority of people living with HIV/AIDS.

Strategies for prevention of mother-to-child transmission of HIV

Over 90 per cent of paediatric HIV infections are maternally acquired, most of these in sub-Saharan Africa. Mortality trends underscore the humanitarian and ethical obligation for urgent global action to protect children from HIV. With the adoption of anti-retroviral therapy in pregnancy, mother-to-child transmission rates have declined to 4-6 per cent in the USA and other industrialised countries. In low-resource settings, where most of the children are continuously being exposed to HIV, the cost of anti-retroviral therapy is prohibitive. Very few developing countries apart from Botswana, Thailand and Brazil have national policies for integration of preventive anti-retroviral therapy in antenatal clinics. This paper reviews anti-retroviral and non-anti-retroviral interventions for prevention of mother-to-child transmission of HIV. To support the health of mothers as well, it supports the implementation of a comprehensive package of care in pregnancy and post-partum, such as access to antenatal and delivery services; anti-retroviral preventive therapy; malaria treatment; family planning; multivitamin, iron and folate supplementation; counselling on feeding options; post-natal care for the child and post-partum care for the mother, and calls for a strategy for advocacy, programme communication and community mobilisation.