Efficacy of antiretroviral drugs in reducing mother-to-child transmission of HIV in Africa: a meta-analysis of published clinical trials

Intergenerational spillover effects of antiretroviral therapy in sub-Saharan Africa: a scoping review and future directions for research

BACKGROUND

Antiretroviral therapy (ART) may influence individuals who do not receive the intervention but who are connected in some way to the person who does. Relatively little is known, however, about the size and scope of, what we term, spillover effects of ART. We explored intergenerational spillover effects of ART in sub-Saharan Africa (SSA) and identified several directions for future research.

METHODS

We conducted a scoping review between March and April 2022. We systematically searched PubMed, PsycINFO, EconLit, OTseeker, AIDSInfo, Web of Science, CINHAL, Google Scholar and African Index Medicus. We analysed the distribution of included studies over time and summarised their findings. We examined the intergenerational impact of ART provision to working-age adults living with HIV on children ('downward' spillover effects) and older adults ('upward' spillover effects). We categorised types of intergenerational spillover effects according to broad themes which emerged from our analysis of included studies.

FINDINGS

We identified 26 studies published between 2005 and 2022 with 16 studies assessing spillover effects from adults to children (downward), and 1 study explicitly assessing spillover effects from working-age adults to older adults (upward). The remaining studies did not fully specify the direction of spillover effects. Most spillover effects of ART to household and family members were beneficial and included improvements in wealth, labour market outcomes, health outcomes and health services utilisation, schooling, and household composition. Both children and older adults benefited from ART availability among adults. Detrimental spillover effects were only reported in three studies and included financial and opportunity costs associated with health services utilisation and food insecurity in the first year after ART.

CONCLUSIONS

ART may lead to substantial spillover effects across generations and sectors in SSA. Further research is needed to capitalise on positive spillover effects while mitigating potential negative spillover effects. The returns to investments in large-scale health interventions such as ART may be underestimated without considering these societal benefits.

Roles of TGF-β1 in Viral Infection during Pregnancy: Research Update and Perspectives

Transforming growth factor-beta 1 (TGF-β1) is a pleiotropic growth factor playing various roles in the human body including cell growth and development. More functions of TGF-β1 have been discovered, especially its roles in viral infection. TGF-β1 is abundant at the maternal-fetal interface during pregnancy and plays an important function in immune tolerance, an essential key factor for pregnancy success. It plays some critical roles in viral infection in pregnancy, such as its effects on the infection and replication of human cytomegalovirus in syncytiotrophoblasts. Interestingly, its role in the enhancement of Zika virus (ZIKV) infection and replication in first-trimester trophoblasts has recently been reported. The above up-to-date findings have opened one of the promising approaches to studying the mechanisms of viral infection during pregnancy with links to corresponding congenital syndromes. In this article, we review our current and recent advances in understanding the roles of TGF-β1 in viral infection. Our discussion focuses on viral infection during pregnancy, especially in the first trimester. We highlight the mutual roles of viral infection and TGF-β1 in specific contexts and possible functions of the Smad pathway in viral infection, with a special note on ZIKV infection. In addition, we discuss promising approaches to performing further studies on this topic.

Optimizing infant HIV diagnosis with additional screening at immunization clinics in three sub-Saharan African settings: a cost-effectiveness analysis

INTRODUCTION

Uptake of early infant HIV diagnosis (EID) varies widely across sub-Saharan African settings. We evaluated the potential clinical impact and cost-effectiveness of universal maternal HIV screening at infant immunization visits, with referral to EID and maternal antiretroviral therapy (ART) initiation.

METHODS

Using the CEPAC-Pediatric model, we compared two strategies for infants born in 2017 in Côte d'Ivoire (CI), South Africa (SA), and Zimbabwe: (1) existing EID programmes offering six-week nucleic acid testing (NAT) for infants with known HIV exposure (EID), and (2) EID plus universal maternal HIV screening at six-week infant immunization visits, leading to referral for infant NAT and maternal ART initiation (screen-and-test). Model inputs included published Ivoirian/South African/Zimbabwean data: maternal HIV prevalence (4.8/30.8/16.1%), current uptake of EID (40/95/65%) and six-week immunization attendance (99/74/94%). Referral rates for infant NAT and maternal ART initiation after screen-and-test were 80%. Costs included NAT ($24/infant), maternal screening ($10/mother-infant pair), ART ($5 to 31/month) and HIV care ($15 to 190/month). Model outcomes included mother-to-child transmission of HIV (MTCT) among HIV-exposed infants, and life expectancy (LE) and mean lifetime per-person costs for children with HIV (CWH) and all children born in 2017. We calculated incremental cost-effectiveness ratios (ICERs) using discounted (3%/year) lifetime costs and LE for all children. We considered two cost-effectiveness thresholds in each country: (1) the per-capita GDP ($1720/6380/2150) per year-of-life saved (YLS), and (2) the CEPAC-generated ICER of offering 2 versus 1 lifetime ART regimens (e.g. offering second-line ART; $520/500/580/YLS).

RESULTS

With EID, projected six-week MTCT was 9.3% (CI), 4.2% (SA) and 5.2% (Zimbabwe). Screen-and-test decreased total MTCT by 0.2% to 0.5%, improved LE by 2.0 to 3.5 years for CWH and 0.03 to 0.07 years for all children, and increased discounted costs by $17 to 22/child (all children). The ICER of screen-and-test compared to EID was $1340/YLS (CI), $650/YLS (SA) and $670/YLS (Zimbabwe), below the per-capita GDP but above the ICER of 2 versus 1 lifetime ART regimens in all countries.

CONCLUSIONS

Universal maternal HIV screening at immunization visits with referral to EID and maternal ART initiation may reduce MTCT, improve paediatric LE, and be of comparable value to current HIV-related interventions in high maternal HIV prevalence settings like SA and Zimbabwe.

Cost-effectiveness of integrating postpartum antiretroviral therapy and infant care into maternal & child health services in South Africa

Background

Poor engagement in postpartum maternal HIV care is a challenge worldwide and contributes to adverse maternal outcomes and vertical transmission. Our objective was to project the clinical and economic impact of integrated postpartum maternal antiretroviral therapy (ART) and pediatric care in South Africa.

Methods

Using the CEPAC computer simulation models, parameterized with data from the Maternal and Child Health–Antiretroviral Therapy (MCH-ART) randomized controlled trial, we evaluated the cost-effectiveness of integrated postpartum care for women initiating ART in pregnancy and their children. We compared two strategies: 1) standard of care (SOC) referral to local clinics after delivery for separate standard ART services for women and pediatric care for infants, and 2) the MCH-ART intervention (MCH-ART) of co-located maternal/pediatric care integrated in Maternal and Child Health (MCH) services throughout breastfeeding. Trial-derived inputs included: 12-month maternal retention in care and virologic suppression (SOC: 49%, MCH-ART: 67%), breastfeeding duration (SOC: 6 months, MCH-ART: 8 months), and postpartum healthcare costs for mother-infant pairs (SOC: $50, MCH-ART: $69). Outcomes included pediatric HIV infections, maternal and infant life expectancy (LE), lifetime HIV-related per-person costs, and incremental cost-effectiveness ratios (ICERs; ICER <US$903/YLS considered “cost-effective”).

Results

Compared to SOC, MCH-ART increased maternal LE (SOC: 25.26 years, MCH-ART: 26.20 years) and lifetime costs (SOC: $9,912, MCH-ART: $10,207; discounted). Projected pediatric outcomes for all HIV-exposed children were similar between arms, although undiscounted LE for HIV-infected children was shorter in SOC (SOC: 23.13 years, MCH-ART: 23.40 years). Combining discounted maternal and pediatric outcomes, the ICER was $599/YLS.

Conclusion

Co-located maternal HIV and pediatric care, integrated in MCH services throughout breastfeeding, is a cost-effective strategy to improve maternal and pediatric outcomes and should be implemented in South Africa.

Off-label Use in Ambulatory Paediatric Clinics in a Central South African Hospital

AIM

The aim of this article was to determine off-label (OL) use in paediatric ambulatory clinics in a South African central hospital.

PATIENTS AND METHODS

OL medicine events were documented in three paediatric clinics (general, highly specialized and dedicated HIV paediatric clinics) at Tygerberg Hospital, South Africa, and analysed according to South African medicine registration information.

RESULTS

There were 2167 medicine events for 658 children. Mean age was 5.6 years (interquartile range 1.8-8.8). There were 123 OL medicine events (6%). Extemporaneous OL use was most common (n = 58, 47%), followed by weight (n = 45, 37%) and lack of paediatric data (n = 38, 31%). Of note was OL use for weight for general paediatrics (n = 32, 78%, p < 0.001), lack of appropriate paediatric data for highly specialized paediatrics (n = 26, 61%, p = 0.004) and extemporaneous use for HIV-infected children (n = 34, 87%, p < 0.001), with significant less OL use for HIV-infected children (p = 0.009).

CONCLUSIONS

Of note is significant extemporaneous OL use in HIV-infected children.

Optimal breastfeeding durations for HIV-exposed infants: the impact of maternal ART use, infant mortality and replacement feeding risk

INTRODUCTION

In 2010, the WHO recommended women living with HIV breastfeed for 12 months while taking antiretroviral therapy (ART) to balance breastfeeding benefits against HIV transmission risks. To inform the 2016 WHO guidelines, we updated prior research on the impact of breastfeeding duration on HIV-free infant survival (HFS) by incorporating maternal ART duration, infant/child mortality and mother-to-child transmission data.

METHODS

Using the Cost-Effectiveness of Preventing AIDS Complications (CEPAC)-Infant model, we simulated the impact of breastfeeding duration on 24-month HFS among HIV-exposed, uninfected infants. We defined "optimal" breastfeeding durations as those maximizing 24-month HFS. We varied maternal ART duration, mortality rates among breastfed infants/children, and relative risk of mortality associated with replacement feeding ("RRRF"), modelled as a multiplier on all-cause mortality for replacement-fed infants/children (range: 1 [no additional risk] to 6). The base-case simulated RRRF = 3, median infant mortality, and 24-month maternal ART duration.

RESULTS

In the base-case, HFS ranged from 83.1% (no breastfeeding) to 90.2% (12-months breastfeeding). Optimal breastfeeding durations increased with higher RRRF values and longer maternal ART durations, but did not change substantially with variation in infant mortality rates. Optimal breastfeeding durations often exceeded the previous WHO recommendation of 12 months.

CONCLUSIONS

In settings with high RRRF and long maternal ART durations, HFS is maximized when mothers breastfeed longer than the previously-recommended 12 months. In settings with low RRRF or short maternal ART durations, shorter breastfeeding durations optimize HFS. If mothers are supported to use ART for longer periods of time, it is possible to reduce transmission risks and gain the benefits of longer breastfeeding durations.

The value of confirmatory testing in early infant HIV diagnosis programmes in South Africa: A cost-effectiveness analysis

BACKGROUND

The specificity of nucleic acid amplification tests (NAATs) used for early infant diagnosis (EID) of HIV infection is <100%, leading some HIV-uninfected infants to be incorrectly identified as HIV-infected. The World Health Organization recommends that infants undergo a second NAAT to confirm any positive test result, but implementation is limited. Our objective was to determine the impact and cost-effectiveness of confirmatory HIV testing for EID programmes in South Africa.

METHOD AND FINDINGS

Using the Cost-effectiveness of Preventing AIDS Complications (CEPAC)-Pediatric model, we simulated EID testing at age 6 weeks for HIV-exposed infants without and with confirmatory testing. We assumed a NAAT cost of US$25, NAAT specificity of 99.6%, NAAT sensitivity of 100% for infants infected in pregnancy or at least 4 weeks prior to testing, and a mother-to-child transmission (MTCT) rate at 12 months of 4.9%; we simulated guideline-concordant rates of testing uptake, result return, and antiretroviral therapy (ART) initiation (100%). After diagnosis, infants were linked to and retained in care for 10 years (false-positive) or lifelong (true-positive). All parameters were varied widely in sensitivity analyses. Outcomes included number of infants with false-positive diagnoses linked to ART per 1,000 ART initiations, life expectancy (LE, in years) and per-person lifetime HIV-related healthcare costs. Both without and with confirmatory testing, LE was 26.2 years for HIV-infected infants and 61.4 years for all HIV-exposed infants; clinical outcomes for truly infected infants did not differ by strategy. Without confirmatory testing, 128/1,000 ART initiations were false-positive diagnoses; with confirmatory testing, 1/1,000 ART initiations were false-positive diagnoses. Because confirmatory testing averted costly HIV care and ART in truly HIV-uninfected infants, it was cost-saving: total cost US$1,790/infant tested, compared to US$1,830/infant tested without confirmatory testing. Confirmatory testing remained cost-saving unless NAAT cost exceeded US$400 or the HIV-uninfected status of infants incorrectly identified as infected was ascertained and ART stopped within 3 months of starting. Limitations include uncertainty in the data used in the model, which we examined with sensitivity and uncertainty analyses. We also excluded clinical harms to HIV-uninfected infants incorrectly treated with ART after false-positive diagnosis (e.g., medication toxicities); including these outcomes would further increase the value of confirmatory testing.

CONCLUSIONS

Without confirmatory testing, in settings with MTCT rates similar to that of South Africa, more than 10% of infants who initiate ART may reflect false-positive diagnoses. Confirmatory testing prevents inappropriate HIV diagnosis, is cost-saving, and should be adopted in all EID programmes.

Prenatal Transmission of Syphilis and Human Immunodeficiency Virus in Brazil: Achieving Regional Targets for Elimination

Background.  The Pan-American Health Organization has called for reducing (1) human immunodeficiency virus (HIV) mother-to-child transmission (MTCT) to ≤0.30 infections/1000 live births (LB), (2) HIV MTCT risk to ≤2.0%, and (3) congenital syphilis (CS) incidence to ≤0.50/1000 LB in the Americas by 2015. Methods.  Using published Brazilian data in a mathematical model, we simulated a cohort of pregnant women from antenatal care (ANC) through birth. We investigated 2 scenarios: "current access" (89.1% receive one ANC syphilis test and 41.1% receive 2; 81.7% receive one ANC HIV test and 18.9% receive birth testing; if diagnosed, 81.0% are treated for syphilis and 87.5% are treated for HIV) and "ideal access" (95% of women undergo 2 HIV and syphilis screenings; 95% receive appropriate treatment). We conducted univariate and multivariate sensitivity analyses on key inputs. Results.  With current access, we projected 2.95 CS cases/1000 LB, 0.29 HIV infections/1000 LB, 7.1% HIV MTCT risk, and 11.11 intrauterine fetal demises (IUFD)/1000 pregnancies, with significant regional variation. With ideal access, we projected improved outcomes: 1.00 CS cases/1000 LB, 0.10 HIV infections/1000 LB, HIV MTCT risk of 2.4%, and 10.65 IUFD/1000 pregnancies. Increased testing drove the greatest improvements. Even with ideal access, only HIV infections/1000 LB met elimination goals. Achieving all targets required testing and treatment >95% and reductions in prevalence and incidence of HIV and syphilis. Conclusions.  Increasing access to care and HIV and syphilis antenatal testing will substantially reduce HIV and syphilis MTCT in Brazil. In addition, regionally tailored interventions reducing syphilis incidence and prevalence and supporting HIV treatment adherence are necessary to completely meet elimination goals.

Medical pluralism predicts non-ART use among parents in need of ART: a community survey in KwaZulu-Natal, South Africa

Despite documented common use of traditional healers and efforts to scale up antiretroviral treatment (ART) in sub-Saharan Africa, evidence on whether medical pluralism predicts ART use is inconclusive and restricted to clinic settings. This study quantitatively assesses whether medical pluralism predicts ART use among parents in need of ART in South Africa. 2,477 parents or primary caregivers of children were interviewed in HIV-endemic communities of KwaZulu-Natal. Analysis used multiple logistic regression on a subsample of 435 respondents in need of ART, who reported either medical pluralism (24.6 %) or exclusive public healthcare use (75.4 %). Of 435 parents needing ART, 60.7 % reported ART use. Medical pluralism emerged as a persistent negative predictor of ART utilization among those needing it (AOR [95 % CI] = .556 [.344 - .899], p = .017). Use of traditional healthcare services by those who need ART may act as a barrier to treatment access. Effective intersectoral collaboration at community level is urgently needed.

Luba-Kasai Men and the Prevention of Mother to Child Transmission (PMTCT) of HIV program in Lusaka

Male participation in the prevention of mother-to-child transmission (PMTCT) of HIV has been determined as one of the key factors in sub-Saharan African countries, but its realization is challenging because of male-related and institutional factors. The purpose of this study is two-fold: first, we explored the views of Luba-Kasai men, living in Zambia in the Lusaka Province, on the factors that encourage, inconvenience or inhibit them in accompanying their wives to the antenatal clinic and their ideas to improve their experience. Secondly, the study considered their knowledge of the PMTCT program and how such knowledge conformed to the Zambian National Protocol Guidelines Integrated PMTCT of HIV /: AIDS. Twenty-one interviews were analyzed using qualitative inductive content analysis. The National Protocol Guidelines Integrated PMTCT of HIV/AIDS were analyzed using the deductive content analysis. The encouraging factors that emerged were involvement in the program, the time of delivery, love and care, and also the suspicion of corruption. The inconveniencing factors were the arrangements and working culture of the clinic, together with stigma and guilt. A lack of motivation, fear of death, socioeconomic circumstances and again the arrangements and working culture at the clinic were held as inhibiting factors. The ideas to remove inconvenient factors were maintaining a spiritual outlook on life, education, interaction, a good mood and a sense of meaningfulness. Considering such male views and paying attention to minorities in the development of national PMTCT of HIV Programs may enhance male participation in the process.

In-home HIV testing and nevirapine dosing by traditional birth attendants in rural Zambia: a feasibility study

INTRODUCTION

Access to lifesaving prevention of mother-to-child transmission (PMTCT) services is problematic in rural Zambia. The simplest intervention used in Zambia has been 2-dose nevirapine (NVP) administration in the peripartum period, a regimen of 1 NVP tablet to the mother at the onset of labor and 1 dose in the form of syrup to the newborn within 4 to 72 hours after birth. This 2-dose regimen has been shown to reduce MTCT by nearly 50%. We set out to demonstrate that in-home HIV testing and NVP dosing by traditional birth attendants (TBAs) is feasible and acceptable by women in rural Zambia.

METHODS

This was a pilot program using TBAs to perform rapid saliva-based HIV testing and administer single-dose NVP in tablet form to the mother at the onset of labor and syrup to the infant after birth.

RESULTS

A total of 280 pregnant women were consented and enrolled into the program, of whom 124 (44.3%) gave birth at home with the assistance of a trained TBA. Of those, 16 (12.9%) were known to be HIV positive, and 101 of the remaining 108 (93.5%) accepted a rapid HIV test. All these women tested HIV negative. In the subset of 16 mothers who were HIV positive, 13 (81.3%) took single-dose NVP administered by a TBA between 1 and 24 hours prior to birth and 100% of exposed newborns (16 of 16) received NVP syrup within 72 hours after birth, 80% of whom were dosed in the first 24 hours of life.

DISCUSSION

With the substantial shortage of human resources in public health care throughout sub-Saharan Africa, it is extremely valuable to utilize lay health care workers to help extended services beyond the level of the facility. Given the high uptake of PMTCT services we believe that TBAs with proper training and support can successfully provide country-approved PMTCT.

Cost-effectiveness of World Health Organization 2010 guidelines for prevention of mother-to-child HIV transmission in Zimbabwe

BACKGROUND

In 2010, the World Health Organization (WHO) released revised guidelines for prevention of mother-to-child human immunodeficiency virus (HIV) transmission (PMTCT). We projected clinical impacts, costs, and cost-effectiveness of WHO-recommended PMTCT strategies in Zimbabwe.

METHODS

We used Zimbabwean data in a validated computer model to simulate a cohort of pregnant, HIV-infected women (mean age, 24 years; mean CD4 count, 451 cells/µL; subsequent 18 months of breastfeeding). We simulated guideline-concordant care for 4 PMTCT regimens: single-dose nevirapine (sdNVP); WHO-recommended Option A, WHO-recommended Option B, and Option B+ (lifelong maternal 3-drug antiretroviral therapy regardless of CD4). Outcomes included maternal and infant life expectancy (LE) and lifetime healthcare costs (2008 US dollars [USD]). Incremental cost-effectiveness ratios (ICERs, in USD per year of life saved [YLS]) were calculated from combined (maternal + infant) discounted costs and LE.

RESULTS

Replacing sdNVP with Option A increased combined maternal and infant LE from 36.97 to 37.89 years and would reduce lifetime costs from $5760 to $5710 per mother-infant pair. Compared with Option A, Option B further improved LE (38.32 years), and saved money within 4 years after delivery ($5630 per mother-infant pair). Option B+ (LE, 39.04 years; lifetime cost, $6620 per mother-infant pair) improved maternal and infant health, with an ICER of $1370 per YLS compared with Option B.

CONCLUSIONS

Replacing sdNVP with Option A or Option B will improve maternal and infant outcomes and save money; Option B increases health benefits and decreases costs compared with Option A. Option B+ further improves maternal outcomes, with an ICER (compared with Option B) similar to many current HIV-related healthcare interventions.

A comparison of frameworks evaluating evidence for global health interventions

Jill Luoto and colleagues apply different frameworks to the same body of evidence for three advocated global health interventions and compare the ratings and policy recommendations resulting from each. Please see later in the article for the Editors' Summary

Highly active anti-retroviral therapy in the prevention of mother-to-child transmission of HIV in rural Zimbabwe during the socio-economic crisis

The purpose of this study is to evaluate the effectiveness of highly active antiretroviral therapy (HAART) in preventing mother-to-child transmission (PMTCT) of HIV in breastfeeding women in rural Zimbabwe. During a severe socio-economic crisis in 2005-2007, 82 eligible HIV-positive pregnant women between 14-36 weeks gestation were initiated on HAART with AZT/3TC/nelfinavir combination therapy at a rural hospital and continued through to six months post-partum. In addition, mothers also received intrapartum single-dose nevirapine (sdNVP). Infants received sdNVP/AZT in the first 72 hours and were assessed for HIV infection at six weeks of age. Results were compared to historical controls of HIV-positive pregnant women who received sdNVP only at the same center. Of the 67 infants with available data on HIV status at six weeks postpartum, three (4.4%) were HIV positive by HIV RNA assay in the HAART + sdNVP group compared to 49/297 (16.5%) in the sdNVP group (p = 0.01). HAART given to HIV-infected mothers in pregnancy and during breastfeeding along with intrapartum sdNVP resulted in a lower postnatal HIV transmission at six weeks postpartum compared to sdNVP treatment. Our HAART regimen demonstrates that PMTCT of HIV can be effective even during times of socioeconomic crisis in resource-poor rural settings.

Promising prevention approaches: tenofovir gel and prophylactic use of antiretroviral medications

Thirty years into the global HIV epidemic, the need for effective prevention strategies remains critical. In July 2010, the CAPRISA-004 study demonstrated that topical administration of a gel containing the antiretroviral agent tenofovir decreased the risk of HIV acquisition among at-risk heterosexual women. Subsequently, the iPrEx study reported that prophylactic use of a daily oral tablet containing tenofovir and emtricitabine reduced the risk of HIV acquisition among high-risk men who have sex with men. These studies illustrate the promise of antiretroviral pre-exposure chemoprophylaxis (PrEP) as an innovative prevention approach. This review discusses the rationale for chemoprophylaxis, compares the advantages of topical and oral delivery, outlines recommended safety monitoring, offers principles to guide selection of antiretroviral agents, and highlights potential unintended consequences of PrEP use. If future studies confirm the safety and efficacy of tenofovir gel and oral PrEP, successful implementation of these strategies could significantly impact the HIV epidemic.

What will it take to eliminate pediatric HIV? Reaching WHO target rates of mother-to-child HIV transmission in Zimbabwe: a model-based analysis

BACKGROUND

The World Health Organization (WHO) has called for the "virtual elimination" of pediatric HIV: a mother-to-child HIV transmission (MTCT) risk of less than 5%. We investigated uptake of prevention of MTCT (PMTCT) services, infant feeding recommendations, and specific drug regimens necessary to achieve this goal in Zimbabwe.

METHODS AND FINDINGS

We used a computer model to simulate a cohort of HIV-infected, pregnant/breastfeeding women (mean age, 24 y; mean CD4, 451/µl; breastfeeding duration, 12 mo). Three PMTCT regimens were evaluated: (1) single-dose nevirapine (sdNVP), (2) WHO 2010 guidelines' "Option A" (zidovudine in pregnancy, infant nevirapine throughout breastfeeding for women without advanced disease, lifelong combination antiretroviral therapy for women with advanced disease), and (3) WHO "Option B" (pregnancy/breastfeeding-limited combination antiretroviral drug regimens without advanced disease; lifelong antiretroviral therapy with advanced disease). We examined four levels of PMTCT uptake (proportion of pregnant women accessing and adhering to PMTCT services): reported rates in 2008 and 2009 (36% and 56%, respectively) and target goals in 2008 and 2009 (80% and 95%, respectively). The primary model outcome was MTCT risk at weaning. The 2008 sdNVP-based National PMTCT Program led to a projected 12-mo MTCT risk of 20.3%. Improved uptake in 2009 reduced projected risk to 18.0%. If sdNVP were replaced by more effective regimens, with 2009 (56%) uptake, estimated MTCT risk would be 14.4% (Option A) or 13.4% (Option B). Even with 95% uptake of Option A or B, projected transmission risks (6.1%-7.7%) would exceed the WHO goal of less than 5%. Only if the lowest published transmission risks were used for each drug regimen, or breastfeeding duration were shortened, would MTCT risks at 95% uptake fall below 5%.

CONCLUSIONS

Implementation of the WHO PMTCT guidelines must be accompanied by efforts to improve access to PMTCT services, retain women in care, and support medication adherence throughout pregnancy and breastfeeding, to approach the "virtual elimination" of pediatric HIV in Zimbabwe. Please see later in the article for the Editors' Summary.

Loss to follow-up in a community clinic in South Africa--roles of gender, pregnancy and CD4 count

BACKGROUND

Faith-based organisations have expanded antiretroviral therapy (ART) in community clinics across South Africa. Loss to follow-up (LTFU), however, limits the potential individual and population treatment benefits and optimal care.

OBJECTIVE

To identify patient characteristics associated with LTFU 6 months after starting ART in a large community clinic.

METHODS

Patients initiating ART between April 2004 and October 2006 in one South African Catholic Bishops' Conference HIV treatment clinic who had at least one follow-up visit were included and routinely monitored every 6 months after ART initiation. Standardised instruments were used to collect data. Rates of LTFU over time were estimated by the Kaplan-Meier method. The Cox proportional hazard regression examined the impact of age, baseline CD4 count, baseline HIV RNA, gender and pregnancy status on LTFU.

RESULTS

Data from 925 patients (age >14 years, median age 36 years, 70% female, of whom 16% were pregnant) were included: 51 (6%) were lost to follow-up 6 months after ART initiation. Younger age (< or = 30 years) (hazard ratio (HR) 2.14, 95% confidence interval (CI) 1.05 - 4.38) and pregnancy for women (HR 3.75, 95% CI 1.53 - 9.16) were significantly associated with higher LTFU rates. When stratified by baseline CD4 count, gender and pregnancy status, pregnant women with lower baseline CD4 counts (< or = 200 cells/microl) had 6.06 times the hazard (95% CI 2.20 - 16.71) of LTFU at 6 months compared with men.

CONCLUSIONS

HIV-infected pregnant women initiating ART were significantly more likely to be lost to follow-up in a community clinic in South Africa. Urgent interventions to successfully retain pregnant women in care are needed.

WHO 2010 guidelines for prevention of mother-to-child HIV transmission in Zimbabwe: modeling clinical outcomes in infants and mothers

BACKGROUND

The Zimbabwean national prevention of mother-to-child HIV transmission (PMTCT) program provided primarily single-dose nevirapine (sdNVP) from 2002-2009 and is currently replacing sdNVP with more effective antiretroviral (ARV) regimens.

METHODS

Published HIV and PMTCT models, with local trial and programmatic data, were used to simulate a cohort of HIV-infected, pregnant/breastfeeding women in Zimbabwe (mean age 24.0 years, mean CD4 451 cells/µL). We compared five PMTCT regimens at a fixed level of PMTCT medication uptake: 1) no antenatal ARVs (comparator); 2) sdNVP; 3) WHO 2010 guidelines using "Option A" (zidovudine during pregnancy/infant NVP during breastfeeding for women without advanced HIV disease; lifelong 3-drug antiretroviral therapy (ART) for women with advanced disease); 4) WHO "Option B" (ART during pregnancy/breastfeeding without advanced disease; lifelong ART with advanced disease); and 5) "Option B+:" lifelong ART for all pregnant/breastfeeding, HIV-infected women. Pediatric (4-6 week and 18-month infection risk, 2-year survival) and maternal (2- and 5-year survival, life expectancy from delivery) outcomes were projected.

RESULTS

Eighteen-month pediatric infection risks ranged from 25.8% (no antenatal ARVs) to 10.9% (Options B/B+). Although maternal short-term outcomes (2- and 5-year survival) varied only slightly by regimen, maternal life expectancy was reduced after receipt of sdNVP (13.8 years) or Option B (13.9 years) compared to no antenatal ARVs (14.0 years), Option A (14.0 years), or Option B+ (14.5 years).

CONCLUSIONS

Replacement of sdNVP with currently recommended regimens for PMTCT (WHO Options A, B, or B+) is necessary to reduce infant HIV infection risk in Zimbabwe. The planned transition to Option A may also improve both pediatric and maternal outcomes.

Combination HIV prevention: significance, challenges, and opportunities

No single HIV prevention strategy will be sufficient to control the HIV pandemic. However, a growing number of interventions have shown promise in partially protecting against HIV transmission and acquisition, including knowledge of HIV serostatus, behavioral risk reduction, condoms, male circumcision, needle exchange, treatment of curable sexually transmitted infections, and use of systemic and topical antiretroviral medications by both HIV-infected and uninfected persons. Designing the optimal package of interventions that matches the epidemiologic profile of a target population, delivering that package at the population level, and evaluating safety, acceptability, coverage, and effectiveness, all involve methodological challenges. Nonetheless, there is an unprecedented opportunity to develop "prevention packages" that combine various arrays of evidence-based strategies, tailored to the needs of diverse subgroups and targeted to achieve high coverage for a measurable reduction in population-level HIV transmission. HIV prevention strategies that combine partially effective interventions should be scaled up and evaluated.

AIDS denialism and public health practice

In this paper, we respond to AIDS denialist arguments that HIV does not cause AIDS, that antiretroviral drugs are not useful, and that there is no evidence of large-scale deaths from AIDS, and discuss the key implications of the relationship between AIDS denialism and public health practice. We provide a brief history of how the cause of AIDS was investigated, of how HIV fulfills Koch's postulates and Sir Bradford Hil's criteria for causation, and of the inconsistencies in alternatives offered by denialists. We highlight clinical trials as the standard for assessing efficacy of drugs, rather than anecdotal cases or discussions of mechanism of action, and show the unanimous data demonstrating antiretroviral drug efficacy. We then show how statistics on mortality and indices such as crude death rate, life expectancy, child mortality, and population growth are consistent with the high mortality from AIDS, and expose the weakness of statistics from death notification, quoted by denialists. Last we emphasize that when denialism influences public health practice as in South Africa, the consequences are disastrous. We argue for accountability for the loss of hundreds of thousands of lives, the need to reform public health practice to include standards and accountability, and the particular need for honesty and peer review in situations that impact public health policy.

Use of antiretrovirals during pregnancy and breastfeeding in low-income and middle-income countries

PURPOSE OF REVIEW

The purpose of the study was to review recent evidence on the use of antiretrovirals during pregnancy and breastfeeding in low-income and middle-income settings.

RECENT FINDINGS

Access to antiretroviral prophylaxis strategies for HIV-infected pregnant women has increased globally, but two-thirds of women in need still do not receive even the simplest regimen for the prevention of mother-to-child transmission of HIV, and most pregnant women in need of antiretroviral treatment do not receive it. The use of combination antiretroviral treatment in pregnancy in low-resource settings is safe and effective, and increasing evidence supports starting ongoing antiretroviral treatment at a CD4 cell count below 350/microl in pregnant women. The use of appropriate short-course antiretroviral prophylactic regimens is effective for prevention of mother-to-child transmission of HIV in women with higher CD4 cell counts. New data on the use of antiretroviral prophylaxis to prevent transmission through breastfeeding demonstrate that both maternal antiretroviral treatment and extended infant prophylaxis are effective.

SUMMARY

Antiretroviral use in pregnancy can benefit mothers in need of treatment and reduce the risk of mother-to-child transmission. Emerging evidence of the effectiveness of antiretroviral prophylaxis in preventing transmission through breastfeeding is encouraging and likely to influence practice in the future.

The past, present, and future of HIV prevention: integrating behavioral, biomedical, and structural intervention strategies for the next generation of HIV prevention

In the past 25 years, the field of HIV prevention research has been transformed repeatedly. Today, effective HIV prevention requires a combination of behavioral, biomedical, and structural intervention strategies. Risk of transmitting or acquiring HIV is reduced by consistent male- and female-condom use, reductions in concurrent and/or sequential sexual and needle-sharing partners, male circumcision, and treatment with antiretroviral medications. At least 144 behavioral prevention programs have been found effective in reducing HIV transmission acts; however, scale up of these programs has not occurred outside of the United States. A series of recent failures of HIV-prevention efficacy trials for biomedical innovations such as HIV vaccines, treating herpes simplex 2 and other sexually transmitted infections, and diaphragm and microbicide barriers highlights the need for behavioral strategies to accompany biomedical strategies. This challenges prevention researchers to reconceptualize how cost-effective, useful, realistic, and sustainable prevention programs will be designed, delivered, tested, and diffused. The next generation of HIV prevention science must draw from the successes of existing evidence-based interventions and the expertise of the market sector to integrate preventive innovations and behaviors into everyday routines.

Meta-analytical studies on the epidemiology, prevention, and treatment of human immunodeficiency virus infection

Since the beginning of the epidemic, extensive research has been conducted in the field of HIV infection. Original research and subsequent meta-analyses have contributed to a better understanding of the disease. Epidemiologic research has shown, for example, that male circumcision reduces the risk of female-to-male transmission. Nevertheless, the question whether circumcision confers protection against HIV transmission in MSM remains open. Studies have shown a positive correlation between HIV and HSV-2 infection. However, a recent RCT found that suppressive antiherpes therapy did not affect rates of HIV acquisition. Meta-analytical studies have advanced the knowledge on the global prevalence of infection among MSM, and disparities among black and white MSM. They have also solidified the evidence that the prophylactic use of ARVs reduces the risk of MTCT. It has also been shown that prolonged ruptured of membranes increases the rates of vertical transmission, and that breastfeeding is associated with postnatal transmission. In addition, prognostic markers of disease progression have been identified. The introduction of ART has resulted in substantial improvements in morbidity and mortality for HIV-seropositive individuals. Several studies have defined recommended and alternative regimens. In a recent meta-analysis it was shown that in treatment naïve patients, NNRTI-based or boosted-PI-based regimens are superior to triple NRTI or unboosted PI-based regimens in terms of virologic suppression. Recent evidence has demonstrated that ART can be successfully used in Africa with better outcomes in those receiving free treatment. Regarding resistance testing in treatment-experienced patients with virologic failure, GRT offers a benefit of small magnitude and there is insufficient evidence to support the use of PRT, in contrast to current guidelines. Meta-analyses have also shown that interventions to improve adherence can be successfully implemented. Finally, the efficacy of the influenza and hepatitis vaccine in the setting of HIV infection has been analyzed. As our knowledge advances, further questions will inevitably arise and will need to be addressed in well-conducted trials.

Update on successes and challenges regarding mother-to-child transmission of HIV

PURPOSE OF REVIEW

There is an unprecedented global commitment to reverse the pediatric HIV epidemic by making prevention of mother-to-child transmission (PMTCT) services accessible in all countries. This review outlines the successes made and the challenges that remain.

RECENT FINDINGS

In resource-rich countries, mother-to-child transmission rates of HIV as low as 1% have been achieved. The efficacy of short-course antiretrovirals for PMTCT in Africa is estimated at 50%. Coinfections with herpes simplex virus type 2, other sexually transmitted infections resulting in genital ulcers, and endemic infectious diseases (e.g., malaria) may increase the risk of mother-to-child transmission of HIV. Vertical transmission of drug-resistant viruses has been reported; the prevalence and effect of transmitted resistant virus on treatment outcomes are under investigation. Obstacles facing PMTCT in resource-limited countries include the lack of healthcare infrastructure, limited manpower, and competing public health priorities with the limited healthcare budget.

SUMMARY

Although the birth of an HIV-infected child in a resource-rich country is now a sentinel health event, in most resource-limited countries the birth of an HIV-infected child continues to be the status quo. Comprehensive PMTCT, including antiretroviral treatment for HIV-infected women and children, should be paramount in resource-limited countries.

Antiretroviral drugs for preventing mother-to-child transmission of HIV in sub-Saharan Africa: balancing efficacy and infant toxicity

OBJECTIVE

Antiretroviral drugs can prevent mother-to-child transmission of HIV infection, but in-utero antiretroviral exposure may be associated with neurologic symptoms due to mitochondrial toxicity. We sought to identify the currently recommended regimen to prevent mother-to-child transmission that optimally balances risks of pediatric HIV infection and neurologic mitochondrial toxicity.

DESIGN

Published MTCT and mitochondrial toxicity data were used in a decision analytic model of MTCT among women in sub-Saharan Africa.

METHODS

We investigated the HIV and mitochondrial toxicity risks associated with no antiretroviral prophylaxis and five recommended regimens ranging from single-dose nevirapine to three-drug antiretroviral therapy (ART). Sensitivity analyses varied all parameters, including infant feeding strategy and the disability of mitochondrial toxicity relative to HIV.

RESULTS

Provision of no antiretroviral drugs is the least effective and least toxic strategy, with 18-month HIV risk of 30.4% and mitochondrial toxicity risk of 0.2% (breastfed infants). With increasing drug number and duration, HIV risk decreases markedly (to 4.9% with three-drug ART), but mitochondrial toxicity risk also increases (to 2.2%, also with three-drug ART). Despite increased toxicity, three-drug ART minimizes total adverse pediatric outcomes (HIV plus mitochondrial toxicity), unless the highest published risks are true for both HIV and mitochondrial toxicity, or the disability from mitochondrial toxicity exceeds 6.4 times that of HIV infection.

CONCLUSION

The risk of pediatric mitochondrial toxicity from effective regimens to prevent mother-to-child transmission is at least an order of magnitude lower than the risk of HIV infection associated with less-effective regimens. Concern regarding mitochondrial toxicity should not currently limit the use of three-drug ART to prevent mother-to-child transmission where it is available.

HIV prevention: What have we learned from community experiences in concentrated epidemics?

Drawing on lessons learned from community experiences in concentrated epidemics, this paper explores three imperatives in the effort to reduce the sexual transmission of HIV: combat prevention fatigue, diversify HIV testing and combat stigma and discrimination. The paper argues for a non-judgmental harm reduction approach to the prevention of sexual transmission of HIV that takes into account the interpretation of risk by diverse individuals and communities in the era of antiretroviral therapy. This approach requires greater attention to increasing access to opportunities to know one's serostatus, especially among key populations at greater risk. Novel approaches to diversifying HIV testing approaches at community level are needed. Finally, the paper makes a plea for bold measures to combat stigma and discrimination, which continues to represent a formidable barrier for access to services for affected populations and may contribute to HIV-related risk behaviours. A "triple therapy" approach to address stigma and discrimination is discussed, which includes greater acceptance of people living with HIV and AIDS (PLWHA), improving relevant laws and policies, and involving prevention users- working with people rather than for people-.Note: this paper corresponds to the plenary talk of Bruno Spire at the XVIIth World AIDS Conference, August 8th, Mexico city: http://www.kaisernetwork.org/health_cast/player.cfm?id=4383.