Extended antiretroviral prophylaxis to reduce breast-milk HIV-1 transmission

Sociocultural and epidemiological aspects of HIV/AIDS in Mozambique

Background

A legacy of colonial rule coupled with a devastating 16-year civil war through 1992 left Mozambique economically impoverished just as the human immunodeficiency virus (HIV) epidemic swept over southern Africa in the late 1980s. The crumbling Mozambican health care system was wholly inadequate to support the need for new chronic disease services for people with the acquired immunodeficiency syndrome (AIDS).

Methods

To review the unique challenges faced by Mozambique as they have attempted to stem the HIV epidemic, we undertook a systematic literature review through multiple search engines (PubMed, Google Scholar™, SSRN, AnthropologyPlus, AnthroSource) using Mozambique as a required keyword. We searched for any articles that included the required keyword as well as the terms 'HIV' and/or 'AIDS', 'prevalence', 'behaviors', 'knowledge', 'attitudes', 'perceptions', 'prevention', 'gender', drugs, alcohol, and/or 'health care infrastructure'.

Results

UNAIDS 2008 prevalence estimates ranked Mozambique as the 8^th most HIV-afflicted nation globally. In 2007, measured HIV prevalence in 36 antenatal clinic sites ranged from 3% to 35%; the national estimate of was 16%. Evidence suggests that the Mozambican HIV epidemic is characterized by a preponderance of heterosexual infections, among the world's most severe health worker shortages, relatively poor knowledge of HIV/AIDS in the general population, and lagging access to HIV preventive and therapeutic services compared to counterpart nations in southern Africa. Poor education systems, high levels of poverty and gender inequality further exacerbate HIV incidence.

Conclusions

Recommendations to reduce HIV incidence and AIDS mortality rates in Mozambique include: health system strengthening, rural outreach to increase testing and linkage to care, education about risk reduction and drug adherence, and partnerships with traditional healers and midwives to effect a lessening of stigma.

New biomedical strategies for HIV-1 prevention in women

Novel HIV-1 prevention strategies continue to be urgently needed. This article reviews the current state of biomedical prevention against HIV-1, focusing on recently completed and ongoing clinical trials of new prevention interventions, particularly those relevant to prevention of HIV-1 in women. Male circumcision, cervical barrier devices, suppressive therapy against herpes simplex virus type 2, treatment of vaginal infections and other vaginal health interventions, pre-exposure antiretroviral prophylaxis, and topical vaginal microbicides are discussed.

Feeding of infants of HIV-positive mothers

PURPOSE OF REVIEW

To highlight recent research that has contributed to an improved understanding of, or resulted in, important changes in the approach to feeding HIV-exposed infants.

RECENT FINDINGS

The administration of antiretroviral therapy to a HIV-positive pregnant woman and its continued use during breast-feeding significantly reduce postnatal HIV transmission to her child. Similarly, extended antiretroviral prophylaxis to the breast-feeding infant dramatically decreases HIV transmission and promotes HIV-free child survival. Predominant breast-feeding may be as effective as exclusive breast-feeding in reducing HIV transmission risk. The protective role of immune modulators such as interferon-gamma and interleukin-15 in preventing breast milk transmission is being better appreciated. Although infant-feeding counseling is critical to the success of infant survival strategies, it is generally done poorly with few examples of successful consequences other than in research settings.

SUMMARY

Breast-feeding of HIV-exposed infants can be made considerably safer in resource-constrained settings through the provision of maternal highly active antiretroviral therapy (HAART), maternal short-course antiretrovirals, and extended infant antiretroviral prophylaxis.

Mother-to-Child HIV Transmission in a Cohort of Pregnant Women Diagnosed by Rapid HIV Testing at Tijuana General Hospital, Baja California, Mexico

This study evaluated an obstetrical program using rapid HIV testing for the prevention of mother-to-child HIV transmission (MTCT) in Baja California, Mexico. Between 2003 and 2005, 45 women in labor and 17 prenatal care women were HIV infected. Among labor patients, 14 (31%) delivered by cesarean section compared with 17 (100%) prenatal care patients (P < .001). Intravenous maternal zidovudine (ZDV) and infant oral ZDV were more frequently administered in prenatal care compared to labor patients: 94% versus 33% (P < .001) and 100% versus 79% (P < .001), respectively. All prenatal care women received combination therapy. All 10 HIV-infected infants were in the labor group, resulting in a MTCT rate of 23% (95% confidence interval [CI] 9.5-34.8) compared to 0% (95% CI 0-1.8; P < .001) among the prenatal care group. Five (50%) of the HIV-infected infants had an AIDS diagnosis and 2 (20%) died within 18 months of birth. Women diagnosed during labor had a high HIV MTCT and poor postnatal outcome.

Elevations in mortality associated with weaning persist into the second year of life among uninfected children born to HIV-infected mothers

BACKGROUND

Early weaning has been recommended to reduce postnatal human immunodeficiency virus (HIV) transmission. We evaluated the safety of stopping breast-feeding at different ages for mortality of uninfected children born to HIV-infected mothers.

METHODS

During a trial of early weaning, 958 HIV-infected mothers and their infants were recruited and followed up from birth to 24 months postpartum in Lusaka, Zambia. One-half of the cohort was randomized to wean abruptly at 4 months, and the other half of the cohort was randomized to continue breast-feeding. We examined associations between uninfected child mortality and actual breast-feeding duration and investigated possible confounding and effect modification.

RESULTS

The mortality rate among 749 uninfected children was 9.4% by 12 months of age and 13.6% by 24 months of age. Weaning during the interval encouraged by the protocol (4-5 months of age) was associated with a 2.03-fold increased risk of mortality (95% confidence interval [CI], 1.13-3.65), weaning at 6-11 months of age was associated with a 3.54-fold increase (95% CI, 1.68-7.46), and weaning at 12-18 months of age was associated with a 4.22-fold increase (95% CI, 1.59-11.24). Significant effect modification was detected, such that risks associated with weaning were stronger among infants born to mothers with higher CD4(+) cell counts (>350 cells/microL).

CONCLUSION

Shortening the normal duration of breast-feeding for uninfected children born to HIV-infected mothers living in low-resource settings is associated with significant increases in mortality extending into the second year of life. Intensive nutritional and counseling interventions reduce but do not eliminate this excess mortality.

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.

Task shifting routine inpatient pediatric HIV testing improves program outcomes in urban Malawi: a retrospective observational study

BACKGROUND

This study evaluated two models of routine HIV testing of hospitalized children in a high HIV-prevalence resource-constrained African setting. Both models incorporated "task shifting," or the allocation of tasks to the least-costly, capable health worker.

METHODS AND FINDINGS

Two models were piloted for three months each within the pediatric department of a referral hospital in Lilongwe, Malawi between January 1 and June 30, 2008. Model 1 utilized lay counselors for HIV testing instead of nurses and clinicians. Model 2 further shifted program flow and advocacy responsibilities from counselors to volunteer parents of HIV-infected children, called "patient escorts." A retrospective review of data from 6318 hospitalized children offered HIV testing between January-December 2008 was conducted. The pilot quarters of Model 1 and Model 2 were compared, with Model 2 selected to continue after the pilot period. There was a 2-fold increase in patients offered HIV testing with Model 2 compared with Model 1 (43.1% vs 19.9%, p<0.001). Furthermore, patients in Model 2 were younger (17.3 vs 26.7 months, p<0.001) and tested sooner after admission (1.77 vs 2.44 days, p<0.001). There were no differences in test acceptance or enrollment rates into HIV care, and the program trends continued 6 months after the pilot period. Overall, 10244 HIV antibody tests (4779 maternal; 5465 child) and 453 DNA-PCR tests were completed, with 97.8% accepting testing. 19.6% of all mothers (n = 1112) and 8.5% of all children (n = 525) were HIV-infected. Furthermore, 6.5% of children were HIV-exposed (n = 405). Cumulatively, 72.9% (n = 678) of eligible children were evaluated in the hospital by a HIV-trained clinician, and 68.3% (n = 387) successfully enrolled into outpatient HIV care.

CONCLUSIONS/SIGNIFICANCE

The strategy presented here, task shifting from lay counselors alone to lay counselors and patient escorts, greatly improved program outcomes while only marginally increasing operational costs. The wider implementation of this strategy could accelerate pediatric HIV care access in high-prevalence settings.

Resumption of sexual activity and regular menses after childbirth among women infected with HIV in Malawi

OBJECTIVE

To determine the factors associated with resumption of sexual activity and regular menses after childbirth among women infected with HIV-1.

METHODS

Information on sociodemographic, behavioral, and clinical factors was obtained from 2 HIV perinatal studies (NVAZ and PEPI trials) conducted in Malawi, 2000-2009. Factors associated with resumption of sexual activity and menses were analyzed using Cox proportional hazard models.

RESULTS

A total of 1838 women from the NVAZ study and 2982 women from the PEPI study were included in the analysis. Resumption of sexual activity was primarily associated with sociodemographic factors (e.g. in the PEPI study, marital status [adjusted hazard ratio (aHR) 0.56, P<0.001], use of contraceptive method [aHR 8.0, P<0.001], and breastfeeding [aHR 0.52, P<0.001]), whereas resumption of regular menses in the PEPI study was primarily associated with biological factors (e.g. plasma viral load [aHR 0.89, P<0.006], and breastfeeding [aHR 0.23, P<0.001).

CONCLUSION

HIV-infected women need adequate counseling to take into account their HIV infection status before resuming sexual activity after childbirth.

Breastfeeding in HIV-positive women: What can be recommended?

Breastfeeding remains a common practice in parts of the world where the burden of HIV is highest and the fewest alternative feeding options exist. The impossible dilemma faced by HIV-positive mothers is whether to breastfeed their infants in keeping with cultural norms but in doing so risk transmitting the virus through breast milk, or to pursue formula feeding, which comes with its own set of risks, including a higher rate of infant mortality from diarrheal illnesses, while reducing transmission of HIV. Treatment of mothers and/or their infants with antiretroviral drugs is a strategy that has been employed for several decades to reduce HIV transmission through pregnancy and delivery, but the effect of these agents when taken during breastfeeding is a newer field of study. In this article we evaluate the latest clinical research, from trials that encourage exclusive breastfeeding to trials of antiretroviral therapy (ART) for either the mother or infant, in an attempt to prevent transmission of HIV through breast milk. Additionally, we discuss research that is in progress, with results anticipated in the next few years that will further shape clinical guidelines and practice. Exclusive breastfeeding is much safer than mixed feeding (the supplementation of breastfeeding with other foods), and should be encouraged even in settings where ART for either the mother or infant is not readily available. The research published regarding maternal treatment with highly active antiretroviral therapy (HAART) during pregnancy and the breastfeeding period has all been non-randomized with relatively little statistical power, but suggests maternal HAART can drastically reduce the risk of transmission of HIV. Infant prophylaxis has been intensively studied in several trials and has been shown to be as effective as maternal treatment with antiretrovirals, reducing the transmission rate after 6 weeks to as low as 1.2%. Research that is in progress will provide us with more answers about the relative contribution of maternal treatment and infant prophylaxis in preventing transmission, and the results of such research may be expected as early as this year through 2013. There is hope that perinatal HIV transmission may be greatly reduced in breastfeeding populations worldwide through a combination of behavioral interventions that encourage exclusive breastfeeding and pharmacologic interventions with antiretrovirals for mothers and/or their infants.

Emergence and persistence of nevirapine resistance in breast milk after single-dose nevirapine administration

OBJECTIVE

Single-dose nevirapine (NVP) (sdNVP) can reduce the risk of HIV vertical transmission. We assessed risk factors for NVP resistance in plasma and breast milk from sdNVP-exposed Ugandan women.

METHODS

Samples were analyzed using the Roche AMPLICOR HIV-1 Monitor Test Kit, version 1.5, and the ViroSeq HIV-1 Genotyping System. NVP concentrations were determined by liquid chromatography with tandem mass spectroscopy.

RESULTS

HIV genotypes (plasma and breast milk) were obtained for 30 women 4 weeks after sdNVP (HIV subtypes: 15A, 1C, 12D, two recombinant). NVP resistance was detected in 12 (40%) of 30 breast milk samples. There was a nonsignificant trend between detection of NVP resistance in breast milk and plasma (P = 0.06). There was no association of HIV resistance in breast milk with median maternal pre-NVP viral load or CD4 cell count, median breast milk viral load at 4 weeks, breast milk sodium more than 10 mmol/l, HIV subtype, or concentration of NVP in breast milk or plasma.

CONCLUSION

NVP resistance was frequently detected in breast milk 4 weeks after sdNVP exposure. In this study, we were unable to identify specific factors associated with breast milk NVP resistance.

Addition of extended zidovudine to extended nevirapine prophylaxis reduces nevirapine resistance in infants who were HIV-infected in utero

BACKGROUND

In the Post-Exposure Prophylaxis of Infants (PEPI)-Malawi trial, most women received single-dose nevirapine (NVP) at delivery, and infants in the extended study arms received single-dose NVP along with 1 week of daily zidovudine (ZDV), followed by either extended daily NVP or extended daily NVP and ZDV up to 14 weeks of age. Although extended NVP prophylaxis reduces the risk of postnatal HIV transmission, it may increase the risk of NVP resistance among infants who are HIV-infected despite prophylaxis.

METHODS

We analyzed 88 infants in the PEPI-Malawi trial who were HIV-infected in utero and who received prophylaxis for a median of 6 weeks prior to HIV diagnosis. HIV genotyping was performed using the ViroSeq HIV Genotyping System.

RESULTS

At 14 weeks of age, the proportion of infants with NVP resistance was lower in the extended NVP and ZDV arm than in the extended NVP arm (28/45, 62.2% vs. 37/43, 86.0%; P = 0.015). None of the infants had ZDV resistance. Addition of extended ZDV to extended NVP was associated with reduced risk of NVP resistance at 14 weeks if prophylaxis was stopped by 6 weeks (54.5 vs. 85.7%, P = 0.007) but not if prophylaxis was continued beyond 6 weeks (83.3 vs. 87.5%, P = 1.00).

CONCLUSION

Addition of extended ZDV to extended NVP prophylaxis significantly reduced the risk of NVP resistance at 14 weeks in infants who were HIV-infected in utero, provided that HIV infection was diagnosed and the prophylaxis was stopped by 6 weeks of age.

Universal antiretroviral therapy for pregnant and breast-feeding HIV-1-infected women: towards the elimination of mother-to-child transmission of HIV-1 in resource-limited settings

Prevention of mother-to-child transmission (MTCT) of human immunodeficiency virus type 1 (HIV-1) remains a challenge in most resource-limited settings, particularly in Africa. Single-dose and short-course antiretroviral (ARV) regimens are only partially effective and have failed to achieve wide coverage despite their apparent simplicity. More potent ARV combinations are restricted to pregnant women who need treatment for themselves and are also infrequently used. Furthermore, postnatal transmission via breast-feeding is a serious additional threat. Modifications of infant feeding practices aim to reduce HIV-1 transmission through breast milk; replacement feeding is neither affordable nor safe for the majority of African women, and early breast-feeding cessation (eg, prior to 6 months of life) requires substantial care and nutritional counseling to be practiced safely. The recent roll out of ARV treatment has changed the paradigm of prevention of MTCT. To date, postnatal ARV interventions that have been evaluated target either maternal ARV treatment to selected breast-feeding women, with good efficacy, or single-drug postexposure prophylaxis for short periods of time to their neonates, with a partial efficacy and at the expense of acquisition of drug-related viral resistance. We hypothesize that a viable solution to eliminate pediatric AIDS lies in the universal provision of fully suppressive ARV regimens to all HIV-1-infected women through pregnancy, delivery, and the entire breast-feeding period. On the basis of available evidence, we suggest translating into practice the recently available evidence on this matter without any further delay.

Breastfeeding, mother-to-child HIV transmission, and mortality among infants born to HIV-Infected women on highly active antiretroviral therapy in rural Uganda

BACKGROUND

Highly active antiretroviral therapy (HAART) drastically reduces mother-to-child transmission of HIV, but where breastfeeding is the only safe infant feeding option, HAART for the prevention of mother-to-child transmission needs to be evaluated in relation to both HIV transmission and infant mortality.

DESIGN AND METHODS

One hundred and two > or = 18-year old women on HAART in rural Uganda who delivered one or more live infants between March 1, 2003 and January 1, 2007 were enrolled in a prospective study to assess HIV transmission and infant survival. All pregnant women were counseled to exclusively breastfeed for 3-6 months according to national guidelines at the time. Infants were followed-up for > or = 7 months and were offered HIV polymerase chain reaction testing quarterly from 6 weeks of age until > or = 6 weeks after complete weaning.

RESULTS

Of 118 infants born during follow-up, 109 (92%) were breastfed. Median durations of exclusive and total breastfeeding were 4 months (interquartile range 3-6) and 5 months (interquartile range 3-7), respectively. None of the infants tested HIV polymerase chain reaction positive over follow-up but 16 infants died without a definitive HIV status at a median age of 2.6 months. In total, 23 (19%) infants died during follow-up at a median age of 3.7 months; 15 (65%) of whom with severe diarrhea and/or vomiting in the week preceding their death. In multivariate analysis, there was a 6-fold greater risk of death among infants breastfed for less than 6 months independent of maternal CD4 count closest to delivery, maternal marital status or maternal death (adjusted hazard ratio = 6.19; 95% confidence interval 1.41-27.0, P = 0.015).

CONCLUSIONS

In resource-constrained settings, HIV-infected pregnant women should be assessed for HAART eligibility and treated as needed without delay, and should be encouraged to breastfeed their infants for at least 6 months.

Illness during pregnancy and bacterial vaginosis are associated with in-utero HIV-1 transmission

HIV-1 transmission in utero accounts for 20-30% of vertical transmission events in breast-feeding populations. In a prospective study of 463 HIV-1-infected mothers and infants, illness during pregnancy was associated with 2.6-fold increased risk of in-utero HIV-1 transmission [95% confidence interval (CI) 1.2-5.8] and bacterial vaginosis with a three-fold increase (95% CI 1.0-7.0) after adjusting for maternal HIV-1 viral load. Interventions targeting these novel risk factors could lead to more effective prevention of transmission during pregnancy.

Infants of human immunodeficiency virus type 1-infected women in rural south India: feeding patterns and risk of mother-to-child transmission

BACKGROUND

We assessed the infant feeding choices of HIV-1-infected women in rural Tamil Nadu, India, and risk factors for mother-to-child transmission of HIV-1.

METHODS

The study population comprised live born infants of HIV-1-infected women from the antenatal clinics of 2 public hospitals in rural Tamil Nadu, India who were enrolled in a prospective cohort study. All women enrolled in the cohort were offered antiretroviral prophylaxis and infant feeding counseling based on WHO/UNAIDS/UNICEF training materials. Infant study visits were scheduled at birth (within the first 24 hours of life), at 1 week, 1 month, and 2 months after birth, and then every 2 months between 4 and 12 months of age.

RESULTS

One-third of women did not breast-feed their infants. Of those who initiated breast-feeding, the median duration of breast-feeding was approximately 3 months. Among those infants who initiated breast-feeding, the proportion exclusively breast-feeding declined from approximately 70% during the first week of life to 0% by the 8 month visit. The observed rate of mother-to-child transmission of HIV-1 in the entire cohort was 6.5% (95% CI: 1.4%-17.9%). The observed HIV-1 incidence among breast-fed infants was 0% (95% CI: 0%-8.9%).

CONCLUSION

The overall transmission rate was relatively low, suggesting effectiveness of antiretroviral transmission prophylaxis. The infant feeding choices made may reflect knowledge gained through the educational program and infant feeding counseling provided. Ensuring HIV-1-infected women receive appropriate HIV-1 treatment (for those who meet criteria for treatment) and access to known efficacious interventions to prevent mother-to-child transmission of HIV-1, are essential.

The development of antiretroviral therapy and its impact on the HIV-1/AIDS pandemic

In the last 25 years, HIV-1, the retrovirus responsible for the acquired immunodeficiency syndrome (AIDS), has gone from being an "inherently untreatable" infectious agent to one eminently susceptible to a range of approved therapies. During a five-year period, starting in the mid-1980s, my group at the National Cancer Institute played a role in the discovery and development of the first generation of antiretroviral agents, starting in 1985 with Retrovir (zidovudine, AZT) in a collaboration with scientists at the Burroughs-Wellcome Company (now GlaxoSmithKline). We focused on AZT and related congeners in the dideoxynucleoside family of nucleoside reverse transcriptase inhibitors (NRTIs), taking them from the laboratory to the clinic in response to the pandemic of AIDS, then a terrifying and lethal disease. These drugs proved, above all else, that HIV-1 infection is treatable, and such proof provided momentum for new therapies from many sources, directed at a range of viral targets, at a pace that has rarely if ever been matched in modern drug development. Antiretroviral therapy has brought about a substantial decrease in the death rate due to HIV-1 infection, changing it from a rapidly lethal disease into a chronic manageable condition, compatible with very long survival. This has special implications within the classic boundaries of public health around the world, but at the same time in certain regions may also affect a cycle of economic and civil instability in which HIV-1/AIDS is both cause and consequence. Many challenges remain, including (1) the life-long duration of therapy; (2) the ultimate role of pre-exposure prophylaxis (PrEP); (3) the cardiometabolic side-effects or other toxicities of long-term therapy; (4) the emergence of drug-resistance and viral genetic diversity (non-B subtypes); (5) the specter of new cross-species transmissions from established retroviral reservoirs in apes and Old World monkeys; and (6) the continued pace of new HIV-1 infections in many parts of the world. All of these factors make refining current therapies and developing new therapeutic paradigms essential priorities, topics covered in articles within this special issue of Antiviral Research. Fortunately, there are exciting new insights into the biology of HIV-1, its interaction with cellular resistance factors, and novel points of attack for future therapies. Moreover, it is a short journey from basic research to public health benefit around the world. The current science will lead to new therapeutic strategies with far-reaching implications in the HIV-1/AIDS pandemic. This article forms part of a special issue of Antiviral Research marking the 25th anniversary of antiretroviral drug discovery and development, Vol. 85, issue 1, 2010.

HIV prevention is not enough: child survival in the context of prevention of mother to child HIV transmission

Clinical and epidemiologic research has identified increasingly effective interventions to reduce mother to child HIV transmission in resource-limited settings These scientific breakthroughs have been implemented in some programmes, although much remains to be done to improve coverage and quality of these programmes. But prevention of HIV transmission is not enough. It is necessary also to consider ways to improve maternal health and protect child survival.

A win-win approach is to ensure that all pregnant and lactating women with CD4 counts of <350 cells/mm³ have access to antiretroviral therapy. On its own, this approach will substantially improve maternal health and markedly reduce mother to child HIV transmission during pregnancy and delivery and through breastfeeding. This approach can be combined with additional interventions for women with higher CD4 counts, either extended prophylaxis to infants or extended regimens of antiretroviral drugs to women, to reduce transmission even further.

Attempts to encourage women to abstain from all breastfeeding or to shorten the optimal duration of breastfeeding have led to increases in mortality among both uninfected and infected children. A better approach is to support breastfeeding while strengthening programmes to provide antiretroviral therapy for pregnant and lactating women who need it and offering antiretroviral drug interventions through the duration of breastfeeding. This will lead to reduced HIV transmission and will protect the health of women without compromising the health and well-being of infants and young children.

Breastfeeding with maternal antiretroviral therapy or formula feeding to prevent HIV postnatal mother-to-child transmission in Rwanda

OBJECTIVE

To assess the 9-month HIV-free survival of children with two strategies to prevent HIV mother-to-child transmission.

DESIGN

Nonrandomized interventional cohort study.

SETTING

Four public health centres in Rwanda.

PARTICIPANTS

Between May 2005 and January 2007, all consenting HIV-infected pregnant women were included.

INTERVENTION

Women could choose the mode of feeding for their infant: breastfeeding with maternal HAART for 6 months or formula feeding. All received HAART from 28 weeks of gestation. Nine-month cumulative probabilities of HIV transmission and HIV-free survival were determined using the Kaplan-Meier method and compared using the log-rank test. Determinants were analysed using a Cox model analysis.

RESULTS

Of the 532 first-liveborn infants, 227 (43%) were breastfeeding and 305 (57%) were formula feeding. Overall, seven (1.3%) children were HIV-infected of whom six were infected in utero. Only one child in the breastfeeding group became infected between months 3 and 7, corresponding to a 9-month cumulative risk of postnatal infection of 0.5% [95% confidence interval (CI) 0.1-3.4%; P = 0.24] with breastfeeding. Nine-month cumulative mortality was 3.3% (95% CI 1.6-6.9%) in the breastfeeding arm group and 5.7% (95% CI 3.6-9.2%) for the formula feeding group (P = 0.20). HIV-free survival by 9 months was 95% (95% CI 91-97%) in the breastfeeding group and 94% (95% CI 91-96%) for the formula feeding group (P = 0.66), with no significant difference in the adjusted analysis (adjusted hazard ratio for breastfeeding: 1.2 (95% CI 0.5-2.9%).

CONCLUSION

: Maternal HAART while breastfeeding could be a promising alternative strategy in resource-limited countries.

Modeling vertical transmission of HIV: imperfect vaccines can be of benefit

Reducing mother to child transmission (MTCT) of HIV in resource poor countries continues to be a major challenge. Here, we construct a hazard model to assess the effectiveness of combinations of HIV vaccine, Nevirapine (NVP), and HIV-specific monoclonal antibody (HIVAB) in reducing MTCT of HIV during the intrapartum and breastfeeding periods. The model shows that an intervention that uses three doses of vaccine with 30% initial immunity and 30% boost effect with subsequent doses (giving rise to maximum immunity approximately 66% with 3 doses) could reduce MTCT to 7.7% when used with NVP and to 5.9% when used with NVP and HIVAB. Using a vaccine with 50% initial immunity and 50% boost can reduce the rate to 4.3%. These results indicate that even an imperfect vaccine, when used in combination with other therapies, can be of considerable benefit in preventing MTCT in resource poor countries.

Duration, pattern of breastfeeding and postnatal transmission of HIV: pooled analysis of individual data from West and South African cohorts

Background

Both breastfeeding pattern and duration are associated with postnatal HIV acquisition; their relative contribution has not been reliably quantified.

Methodology and Principal Findings

Pooled data from 2 cohorts: in urban West Africa where breastfeeding cessation at 4 months was recommended but exclusive breastfeeding was rare (Ditrame Plus, DP); in rural South Africa where high rates of exclusive breastfeeding were achieved, but with longer duration (Vertical Transmission Study, VTS). 18-months HIV postnatal transmission (PT) was estimated by Kaplan-Meier in infants who were HIV negative, and assumed uninfected, at age >1 month. Censoring with (to assess impact of mode of breastfeeding) and without (to assess effect of breastfeeding duration) breastfeeding cessation considered as a competing event. Of 1195 breastfed infants, not HIV-infected perinatally, 38% DP and 83% VTS children were still breastfed at age 6 months. By age 3 months, 66% of VTS children were exclusively breastfed since birth and 55% of DP infants predominantly breastfed (breastmilk+water-based drinks). 18-month PT risk (95%CI) in VTS was double that in DP: 9% (7–11) and 5% (3–8), respectively (p = 0.03). However, once duration of breastfeeding was allowed for in a competing risk analysis assuming that all children would have been breastfed for 18-month, the estimated PT risk was 16% (8–28) in DP and 14% (10–18) in VTS (p = 0.32). 18-months PT risk was 3.9% (2.3–6.5) among infants breastfed for less than 6 months, and 8.7% (6.8–11.0) among children breastfed for more than 6 months; crude hazard ratio (HR): 2.1 (1.2–3.7), p = 0.02; adjusted HR 1.8 (0.9–3.4), p = 0.06. In individual analyses of PT rates for specific breastfeeding durations, risks among children exclusively breastfed were very similar to those in children predominantly breastfed for the same period. Children exposed to solid foods during the first 2 months of life were 2.9 (1.1–8.0) times more likely to be infected postnatally than children never exposed to solids this early (adjusted competing risk analysis, p = 0.04).

Conclusions

Breastfeeding duration is a major determinant of postnatal HIV transmission. The PT risk did not differ between exclusively and predominantly breastfed children; the negative effect of mixed breastfeeding with solids on PT were confirmed.

Cost-effectiveness of routine rapid human immunodeficiency virus antibody testing before DNA-PCR testing for early diagnosis of infants in resource-limited settings

BACKGROUND

Infants born to HIV-infected women should receive HIV testing to allow early diagnosis and treatment. Recommendations for resource-limited settings stress laboratory-based virologic assays. While effective, these tests are logistically complex and expensive. This study explored the cost-effectiveness of incorporating initial screening with rapid HIV tests (RHT) into the conventional testing algorithm to screen-out HIV-uninfected infants, thereby reducing the need for costly virologic testing.

METHODS

Data on HIV prevalence, RHT sensitivity and specificity, and costs were collected from 820 HIV-exposed children (1.5-18 months) attending 2 postnatal screening programs in Uganda during July 2005 to December 2006. Cost-effectiveness models compared the conventional testing algorithm DNA polymerase chain reaction (DNA-PCR with Roche Amplicor v1.5) with a modified algorithm (initial RHT to screen-out HIV-uninfected infants before DNA-PCR).

RESULTS

The model estimated that the conventional algorithm would identify 94.3% (91.8%-94.7%) of HIV-infected infants, compared with 87.8% (79.4%-90.5%) for a modified algorithm using RHT (HIV 1/2 Determine) and excluding the need for DNA-PCR for HIV antibody-negative infants. Costs per infant were $23.47 ($23.32-$23.76) for the conventional algorithm and between $22.75 ($21.89-$23.31) and $7.58 ($6.41-$10.75) for the modified algorithm, depending on infant age and symptoms. Compared with the conventional algorithm, costs per HIV-infected infant identified using the modified algorithm were higher in 1.5-to 3-month-old infants, but significantly lower in 3-month-old and older infants. Models replicating the whole infant testing program showed the modified algorithm would have marginally lower sensitivity, but would reduce total program costs by 27% to 40%, producing an incremental cost-effectiveness ratio of $1489 ($686-$6781) for the conventional versus modified algorithms.

CONCLUSIONS

Screening infants with RHT before DNA-PCR is cost-effective in infants 3 months old or older. Incorporating RHT into early infant testing programs could improve cost-effectiveness and reduce program costs.

Lower risk of resistance after short-course HAART compared with zidovudine/single-dose nevirapine used for prevention of HIV-1 mother-to-child transmission

BACKGROUND

Antiretroviral resistance after short-course regimens used to prevent mother-to-child transmission has consequences for later treatment. Directly comparing the prevalence of resistance after short-course regimens of highly active antiretroviral therapy (HAART) and zidovudine plus single-dose nevirapine (ZDV/sdNVP) will provide critical information when assessing the relative merits of these antiretroviral interventions.

METHODS

In a clinical trial in Kenya, pregnant women were randomized to receive either ZDV/sdNVP or a short-course of HAART through 6 months of breastfeeding. Plasma samples were collected 3-12 months after treatment cessation, and resistance to reverse transcriptase inhibitors was assessed using both a sequencing assay and highly sensitive allele-specific polymerase chain reaction assays.

RESULTS

No mutations associated with resistance were detectable by sequencing in either the ZDV/sdNVP or HAART arms at 3 months posttreatment, indicating that resistant viruses were not present in >20% of virus. Using allele-specific polymerase chain reaction assays for K103N and Y181C, we detected low levels of resistant virus in 75% of women treated with ZDV/sdNVP and only 18% of women treated with HAART (P = 0.007). Y181C was more prevalent than K103N at 3 months and showed little evidence of decay by 12 months.

CONCLUSIONS

Our finding provides evidence that compared with ZDV/sdNVP, HAART reduces but does not eliminate nevirapine resistance.

Growth faltering due to breastfeeding cessation in uninfected children born to HIV-infected mothers in Zambia

BACKGROUND

The effect of breastfeeding on growth in HIV-exposed infants is not well described.

OBJECTIVE

The objective was to evaluate the effect of early breastfeeding cessation on growth.

DESIGN

In a trial conducted in Lusaka, Zambia, HIV-infected mothers were randomly assigned to exclusive breastfeeding for 4 mo followed by rapid weaning to replacement foods or exclusive breastfeeding for 6 mo followed by introduction of complementary foods and continued breastfeeding for a duration of the mother's choice. Weight-for-age z score (WAZ), length-for-age z score (LAZ), and weight-for-length z score (WLZ) and the self-reported breastfeeding practices of 593 HIV-uninfected singletons were analyzed. Generalized estimating equations were used to adjust for confounders.

RESULTS

WAZ scores declined precipitously between 4.5 and 15 mo. The decline was slower in the breastfed infants. At 9, 12, and 15 mo, mean WAZs were, respectively, -0.74, -0.92, and -1.06 in infants who were reportedly breastfed and were -1.07, -1.20, and -1.31 in the weaned infants (P = 0.003, 0.007, and 0.02, respectively). No differences were observed past 15 mo. Breastfeeding practice was not associated with LAZ, which declined from -0.98 to -2.24 from 1 to 24 mo. After adjustment for birth weight, maternal viral load, body mass index, education, season, and marital and socioeconomic status, not breastfeeding was associated with a 0.28 decline in WAZ between 4.5 and 15 mo (P < 0.0001). During the rainy season, not breastfeeding was associated with a larger WAZ decline (0.33) than during the dry season (0.22; P for interaction = 0.02).

CONCLUSIONS

Early growth is compromised in uninfected children born to HIV-infected Zambian mothers. Continued breastfeeding partially mitigates this effect through 15 mo. Nutritional interventions to complement breastfeeding after 6 mo are urgently needed. This trial was registered at clinicaltrials.gov as NCT00310726.

Tuberculosis and tuberculosis/HIV co-infection in pregnancy

Both tuberculosis (TB) and human immunodeficiency virus (HIV) affect women aged 15-29 years. This is the prime childbearing age group with an increasing mortality due to HIV. The key to the prevention of neonatal TB among these women is early recognition of TB, based primarily on maternal history and relevant investigations of the mother and newborn. There are World Health Organization (WHO) guidelines for maternal prophylaxis and therapy and prophylaxis to the newborn on the stage of the maternal disease. In HIV-infected women, CD4 counts should be monitored urgently as a guide to antiretroviral (ARV) prophylaxis. When the CD4 count is <200 cells/mm(3), WHO recommends that the mother should be treated with combination antiretroviral therapy (cART). In resource-rich settings most guidelines recommend treatment with cART when the CD4 count is <350 cells/mm(3). The combination of ARVs and anti-TB therapy poses difficulties which can be resolved by combination of different drugs. In both conditions, evidence suggests that in resource-limited settings exclusive breastfeeding is recommended, with the addition of flash heating of the mothers' milk for HIV-infected women.

Current issues in prevention of mother-to-child transmission of HIV-1

PURPOSE OF REVIEW

To review new evidence in prevention of mother-to-child-transmission of HIV-1, which establishes, in principle, the feasibility of greatly improved effectiveness in developing countries.

RECENT FINDINGS

This review presents evidence that demonstrates that a large gap in prevention of mother-to-child-transmission [MTCT] is being increasingly bridged. Recent studies have addressed issues on postnatal transmission of HIV-1 through breastfeeding. Breastfeeding transmission affects the majority of HIV-infected pregnant women and children in the world and who live in Africa and are often poor. Prevention of unwanted pregnancies in all women living in high HIV prevalence regions will probably reduce the risk of HIV-positive pregnancies. These studies demonstrate the success of the following three types of interventions:primary prevention of HIV-1 in women;prophylaxis with antiretroviral drugs in breastfeeding infants;prophylaxis with antiretroviral drugs for lactating mothers.It is also clear that key barriers to implementing these findings in developing countries are weak and ineffectual health systems. Therefore, identifying needs for improving health service delivery are critical; an example of the synergy between prevention and treatment through integrated services is given.

SUMMARY

Recent data on primary prevention of HIV-1 in women of child-bearing age, and use of antiretrovirals in breastfeeding infants and lactating mothers, report successful interventions for the prevention of breastfeeding transmission of HIV-1. Health infrastructure improvement in developing countries is central to the application of research findings to implementation of MTCT programmes.

An update on HIV and infant feeding issues in developed and developing countries

The field of mother to child transmission of human-immunodeficiency virus is rapidly evolving. In the United States, prevention focuses on implementation of universal human-immunodeficiency virus testing to assure compliance with recommended treatment regimens and infant-feeding strategies. In most cases, this is the avoidance of all breastfeeding. In developing countries, avoidance of breastfeeding places infants at higher risk of morbidity and mortality. Current World Health Organization recommendations require individualized counseling to determine the best feeding method for each woman.

Advances and failures in preventing perinatal human immunodeficiency virus infection

An estimated 2.5 million children are currently living with HIV, the vast majority as a result of mother-to-child transmission. Prevention of perinatal HIV infection has been immensely successful in developed countries. A comprehensive package of services, including maternal and infant antiretroviral therapy, elective cesarean section, and avoidance of breast-feeding, has resulted in transmission rates of less than 2%. However, in developing countries, access to such services is often not available, as demonstrated by the fact that the vast majority of children with HIV live in Africa. Over the past few years, many developing nations have made great strides in improving access to much-needed services. Notably, in eastern and southern Africa, the regions most affected by HIV, mother-to-child-transmission coverage rates for HIV-positive women increased from 11% in 2004 to 31% in 2006. These successes are deserving of recognition, while not losing sight of the fact that much remains to be done; currently, an estimated 75% of pregnant women worldwide have an unmet need for antiretroviral therapy. Further work is needed to determine the optimal strategy for reducing perinatal transmission among women in resource-poor settings, with a particular need for reduction of transmission via breast-feeding.

Differential effects of early weaning for HIV-free survival of children born to HIV-infected mothers by severity of maternal disease

Background

We previously reported no benefit of early weaning for HIV-free survival of children born to HIV-infected mothers in intent-to-treat analyses. Since early weaning was poorly accepted, we conducted a secondary analysis to investigate whether beneficial effects may have been hidden.

Methods

958 HIV-infected women in Lusaka, Zambia, were randomized to abrupt weaning at 4 months (intervention) or to continued breastfeeding (control). Children were followed to 24 months with regular HIV PCR tests and examinations to determine HIV infection or death. Detailed behavioral data were collected on when all breastfeeding ended. Most participants were recruited before antiretroviral treatment (ART) became available. We compared outcomes among mother-child pairs who weaned earlier or later than intended by study design adjusting for potential confounders.

Results

Of infants alive, uninfected and still breastfeeding at 4 months in the intervention group, 16.1% who weaned as instructed acquired HIV or died by 24 months compared to 16.0% who did not comply (p = 0.98). Children of women with less severe disease during pregnancy (not eligible for ART) had worse outcomes if their mothers weaned as instructed (RH = 2.60 95% CI: 1.06–6.36) compared to those who continued breastfeeding. Conversely, children of mothers with more severe disease (eligible for ART but did not receive it) who weaned early had better outcomes (p-value interaction = 0.002). In the control group, weaning before 15 months was associated with 3.94-fold (95% CI: 1.65–9.39) increase in HIV infection or death among infants of mothers with less severe disease.

Conclusion

Incomplete adherence did not mask a benefit of early weaning. On the contrary, for women with less severe disease, early weaning was harmful and continued breastfeeding resulted in better outcomes. For women with more advanced disease, ART should be given during pregnancy for maternal health and to reduce transmission, including through breastfeeding.

Trial Registration

Clinical trials.gov NCT00310726

Improving mothers' access to PMTCT programs in West Africa: a public health perspective

Despite technical means and apparent political will, the percentage of pregnant women involved in preventing mother-to-child transmission (PMTCT) interventions is not increasing as fast as public health authorities would expect. This is even more striking when compared to the scaling up of access to antiretroviral treatment. It seems important to analyze the successes and failures of the programs and the "scaling-up" of PMTCT programs. This is a major issue for women at two levels: women are very concerned about the health of their children, and they are the ones who implement prevention in collaboration with health services. A review of achievements and failures described from a public health perspective may lead to greater understanding of the social aspects involved in PMTCT program achievements and failures. This paper is based on the combination of a literature review and empirical evidence collected during 15 years of PMTCT implementation, childcare research and treatment programs in West Africa. The analysis aims to identify the social issues that explain the gap between PMTCT program aims and achievements in order to encourage research in the social sciences regarding relationships between mothers and the care system. We find it is possible to build programs at the national level that have a high degree of acceptance of testing and intervention, with a progressive decline in HIV infection among children. However, many obstacles remain, highlighting the necessity to broaden access to HIV screening, develop mass campaigns on testing for couples and improve HIV care and training for caregivers. Because HIV-infected pregnant women are experiencing great psychological distress, healthcare providers must use an approach that is as friendly as possible.

Management of paediatric HIV-1 resistance

PURPOSE OF REVIEW

Children have higher rates of virological failure than adults, often associated with more extensive resistance and limited second-line options. In order to maintain clinical benefits of highly active antiretroviral therapy (HAART) into adulthood, particularly for children starting at a young age, strategies are needed to limit the emergence of resistance and to offer highly effective subsequent lines of therapy. Similarly, well resourced settings face challenges regarding extensive resistance accumulated over the past decade or more, particularly resulting from suboptimal therapies.

RECENT FINDINGS

Rates of resistance at failure of nonnucleoside reverse-transcriptase inhibitor based HAART are higher in developing countries than in well resourced settings. In the latter, second-generation protease inhibitors tipranavir and darunavir are promising, with tipranavir now licensed for those above 2 years and darunavir showing good trial results in children above 6 years. However, combination with new classes such as integrase inhibitors (currently in phase I trials) and CCR5 antagonists (no paediatric data yet) will probably be necessary to gain maximal long-term benefits.

SUMMARY

Common goals in paediatric HIV for both resource-rich and resource-limited settings are to limit vertical transmission, minimize emergence of resistant viruses in both mother and child where prevention of mother-to-child transmission fails, and limit resistance in children starting HAART. Optimal sequencing of regimens in the absence of resistance testing is a priority research area. Paediatric studies using newer classes of agents are of paramount importance, as well as expanding access to existing antiretrovirals.

Operational effectiveness of guidelines on complete breast-feeding cessation to reduce mother-to-child transmission of HIV: results from a prospective observational cohort study at routine prevention of mother-to-child transmission sites, South Africa

OBJECTIVE

Until 2006, HIV-positive women who chose to exclusively breast-feed were advised to completely stop breast-feeding by 6 months. We investigated operational feasibility and predictors of complete breast-feeding cessation (CBC).

DESIGN

A prospective observational cohort study at 3 routine prevention of mother-to-child transmission sites, South Africa.

METHODS

Data on "complete breast-feeding cessation at 24 weeks" and "not breast-feeding (NBF) for 4 days before the last follow-up visit at or before 24 weeks" were gathered during home visits (3, 5, 7, 9, 12, 16, 20, and 24 weeks). The main subgroup of interest for this analysis was women practicing exclusive breast-feeding/predominant breast-feeding at 3 weeks. Univariate analysis, logistic regression, Kaplan-Meier Survival analysis, and Cox regression were performed.

RESULTS

Eighty-eight women (43.6%) reported CBC. "Health staff suggesting formula use: [OR(a) 4.39 (1.76-10.97)] and "infant hospitalization" [OR(a) 3.27 (1.37-7.79)] were the only significant predictors of CBC. The probability of NBF at 5, 7, 9, 12, 16, 20, and 24 weeks was 2.8% [95% confidence interval (CI) 1.8% to 3.8%], 4.3% (3.0% to 5.6%), 5.9% (4.4% to 7.4%, 9.8% (7.9% to 11.7%), 16.1 (13.8% to 18.4%), 23.1% (20.5% to 25.7%), and 37.6% (34.6% to 40.6%), respectively. Infant HIV status [hazard ratio 5.5 95% CI 2.4 to 12.5] was the only predictor of infant death. NBF was not protective against 9-month infant HIV or death in univariate and multivariable analysis.

CONCLUSIONS

At programmatic level, CBC by 24 weeks is uncommon, and success seems unrelated to predetermined social, economic, and environmental (acceptable, feasible, affordable, sustainable, and safe AFASS) criteria. Thus at this level, activities that encourage CBC (amongst women meeting AFASS criteria) need to be identified and tested.

Timing and determinants of mother-to-child transmission of HIV in Nigeria

OBJECTIVE

To characterize the timing and determinants of mother-to-child transmission (MTCT) of HIV among mothers receiving single-dose nevirapine to prevent MTCT in Nigeria.

METHODS

Three hundred and seventy-one HIV-infected mothers and their infants were followed from birth, at 1 week, and at 1, 3, 6, and 12 months. Risks of in utero (IU), intrapartum (IP/EPP), and postnatal (PP) transmission were quantified using conditional Cox regressions.

RESULTS

Maternal viral load was the only risk factor for IU transmission after controlling for known risk factors. Low birth weight, premature birth, mixed feeding, and maternal viral load were associated with IP/EPP transmission. Increased PP transmission was associated with low birth weight and mixed feeding. At 6 months, mixed-fed infants were more likely to acquire infection than formula-fed infants (hazard ratio=5.74; 95% CI, 1.26-26.2).

CONCLUSION

Risk factors for IU transmission differed from those of IP and PP transmission. Reducing mixed feeding and low birth weight delivery among HIV-infected mothers can further decrease IP and PP transmission.

Risk factors for early and late transmission of HIV via breast-feeding among infants born to HIV-infected women in a randomized clinical trial in Botswana

Risk factors for mother-to-child transmission (MTCT) of human immunodeficiency virus (HIV) via breast-feeding were evaluated in a randomized trial. HIV-infected women and their infants received zidovudine as well as single-dose nevirapine or placebo. Infants were randomized to formula-feed (FF) or breast-feed (BF) in combination with zidovudine prophylaxis. Of 1116 at-risk infants, 6 (1.1%) in the FF group and 7 (1.3%) in the BF group were infected between birth and 1 month (P=.99). Maternal receipt of nevirapine did not predict early MTCT in the BF group (P=.45). Of 547 infants in the BF group at risk for late MTCT, 24 (4.4%) were infected. Maternal HIV-1 RNA levels in plasma (P<.001) and breast milk (P<.001) predicted late MTCT. These findings support the safety of 1 month of breast-feeding in combination with maternal and infant antiretroviral prophylaxis. Trial registration. ClinicalTrials.gov identifiers: NCT00197691 and NCT00197652.