Preventing mother-to-child transmission of HIV-1 in Africa in the year 2000

Knowledge and perception of Prevention of Mother to Child services amongst pregnant women accessing antenatal clinic in a Primary Health Care centre in Nigeria

Background

Few studies have assessed pregnant women's perceptions regarding prevention of mother to child of HIV and the available services at the primary health care level in Nigeria.

Objective

Assessment of knowledge and perception of antenatal clinic (ANC) attendees regarding Prevention of Mother to Child Transmission (PMTCT) of HIV at primary health care facilities in south-west Nigeria.

Method

A cross-sectional survey was conducted amongst 400 antenatal attendees in a Primary Health Care centre in Ibadan, Nigeria.

Results

Known methods of PMTCT were: use of anti-retroviral treatment (ART) during pregnancy (75.0%), ART at birth (65.8%) and not breastfeeding (61.8%). Previous HIV Counselling and Testing (HCT) was reported by 71%, significantly higher proportions of those who were married, in the third trimester of pregnancy or engaged in professional and/or skilled occupations had been tested. Regarding the HCT services provided, 92.2% understood the HIV-related health education provided, 89.7.2% reported that the timing was appropriate, 92.6% assessed the nurses’ approach as acceptable but 34.0% felt the test was forced upon them. Majority (79.6%) were aware of non-breastfeeding options of infant feeding, but only 3.5% were aware of exclusive breastfeeding for a stipulated period as an infant feeding option. Nevertheless, the majority of the women found the non-breast feeding option culturally unacceptable.

Conclusion

Women in this survey were knowledgeable about the methods of PMTCT, but had negative perceptions regarding certain aspects of the HCT services and the recommended non-breastfeeding infant feeding option. Health workers should provide client friendly services and infant feeding counselling that is based on current WHO recommendations and culturally acceptable.

Mortality of HIV-infected and uninfected children in a longitudinal cohort in rural south-west Uganda during 8 years of follow-up

OBJECTIVES

To determine the impact of HIV on child mortality and explore potential risk factors for mortality among HIV-infected and HIV-exposed uninfected children in a longitudinal cohort in rural Uganda.

METHODS

From July 2002 to March 2010, HIV-infected and HIV-exposed uninfected children aged 6 weeks-13 years were enrolled in an open population-based clinical cohort. Antiretroviral therapy (ART) was introduced in 2005. Clinical and laboratory data were collected every 3 months. Person-years at risk were calculated from time of enrolment until earliest date of ART initiation, death or last visit. Cox regression was used to estimate hazard ratios (HR) for mortality.

RESULTS

Eighty-nine (30.2%) HIV-infected and 206 (69.8%) HIV-exposed but uninfected children were enrolled. Twenty-one children died. The mortality rate was six times higher in ART-naive HIV-infected children than in HIV-exposed but uninfected children (HR = 6.4, 95% CI = 2.4-16.6). Among HIV-infected children, mortality was highest in those aged <2 years. Decreasing weight-for-age Z (WAZ) score was the strongest risk factor for mortality among HIV-infected children (HR for unit decrease in WAZ = 2.6, 95% CI = 1.6-4.1). Thirty-five children (aged 7 months-15.6 years; median, 5.4 years) started ART.

CONCLUSIONS

Mortality among HIV-infected children was highest among those aged <2 years. Intensified efforts to prevent mother-to-child transmission of HIV and ensure early HIV diagnosis and treatment are required to decrease child mortality caused by HIV in rural Africa.

Young and vulnerable: spatial-temporal trends and risk factors for infant mortality in rural South Africa (Agincourt), 1992-2007

BACKGROUND

Infant mortality is an important indicator of population health in a country. It is associated with several health determinants, such as maternal health, access to high-quality health care, socioeconomic conditions, and public health policy and practices.

METHODS

A spatial-temporal analysis was performed to assess changes in infant mortality patterns between 1992-2007 and to identify factors associated with infant mortality risk in the Agincourt sub-district, rural northeast South Africa. Period, sex, refugee status, maternal and fertility-related factors, household mortality experience, distance to nearest primary health care facility, and socio-economic status were examined as possible risk factors. All-cause and cause-specific mortality maps were developed to identify high risk areas within the study site. The analysis was carried out by fitting Bayesian hierarchical geostatistical negative binomial autoregressive models using Markov chain Monte Carlo simulation. Simulation-based Bayesian kriging was used to produce maps of all-cause and cause-specific mortality risk.

RESULTS

Infant mortality increased significantly over the study period, largely due to the impact of the HIV epidemic. There was a high burden of neonatal mortality (especially perinatal) with several hot spots observed in close proximity to health facilities. Significant risk factors for all-cause infant mortality were mother's death in first year (most commonly due to HIV), death of previous sibling and increasing number of household deaths. Being born to a Mozambican mother posed a significant risk for infectious and parasitic deaths, particularly acute diarrhoea and malnutrition.

CONCLUSIONS

This study demonstrates the use of Bayesian geostatistical models in assessing risk factors and producing smooth maps of infant mortality risk in a health and socio-demographic surveillance system. Results showed marked geographical differences in mortality risk across a relatively small area. Prevention of vertical transmission of HIV and survival of mothers during the infants' first year in high prevalence villages needs to be urgently addressed, including expanded antenatal testing, prevention of mother-to-child transmission, and improved access to antiretroviral therapy. There is also need to assess and improve the capacity of district hospitals for emergency obstetric and newborn care. Persisting risk factors, including inadequate provision of clean water and sanitation, are yet to be fully addressed.

Effect of maternal HIV status on infant mortality: evidence from a 9-month follow-up of mothers and their infants in Zimbabwe

OBJECTIVE

To describe infant mortality trends and associated factors among infants born to mothers enrolled in a prevention of mother-to-child transmission (PMTCT) program.

STUDY DESIGN

A nested case-control study of human immunodeficiency virus (HIV)-positive and -negative pregnant women enrolled from the national PMTCT program at 36 weeks of gestation attending three peri-urban clinics in Zimbabwe offering maternal and child health care. Mother-infant pairs were followed up from delivery, and at 6 weeks, 4 months and 9 months.

RESULTS

A total of 1045 mother and singleton infant pairs, 474 HIV-positive and 571 HIV-negative mothers, delivered 469 and 569 live infants, respectively. Differences in mortality were at 6 weeks and 4 months, RR (95% CI) 9.71 (1.22 to 77.32) and 21.84 (2.93 to 162.98), respectively. Overall, 9-month mortality rates were 150 and 47 per 1000 person-years for infants born to HIV-positive and HIV-negative mothers, respectively. Proportional hazard ratio of mortality for children born to HIV-positive mothers was 3.21 (1.91 to 5.38) when compared with that for children born to HIV-negative mothers.

CONCLUSION

Maternal HIV exposure was associated with higher mortality in the first 4 months of life. Infant's HIV status was the strongest predictor of infant mortality. There is a need to screen infants for HIV from delivery and throughout breastfeeding.

Vertically acquired paediatric HIV infection: the challenges of providing comprehensive packages of care in resource-limited settings

The successes achieved in paediatric disease management in well-resourced countries in recent years highlight the vast divide between the care options, and ultimately survival, between developed and developing areas of the world. Using an extensive literature review, we quantify recent achievements in terms of improved survival and quality of life, and examine current evidence of the effects of treatment on the survival and morbidity of HIV-infected children in developing countries. When provided with the same care as their counterparts in developed countries, children in developing countries show similar improvements in survival and general health, with 1-year survival rates exceeding 90% in many African settings. Despite the challenges of providing comprehensive packages of care in resource-limited settings, there is an urgent need to scale up prevention and treatment of HIV infections in children, focussing on strengthening Prevention of Mother-to-Child Transmission programmes in order to reduce the numbers of infants who are infected in addition to reducing morbidity and mortality among their mothers.

Estimating the number of vertically HIV-infected children eligible for antiretroviral treatment in resource-limited settings

BACKGROUND

With the gradual roll-out of antiretroviral therapy (ART) to delay progression of HIV disease in children in programmes across sub-Saharan Africa and resource-limited settings elsewhere, reliable information on the number of vertically infected children eligible for such treatment is urgently required.

METHODS

We present a model to estimate the number of vertically HIV-infected children by age who have progressed to moderate to severe disease (MSD) and as such are eligible for ART on the basis of clinical disease, allowing for: antenatal HIV prevalence, use of interventions to prevent mother-to-child transmission (PMTCT), infant feeding policies and availability of co-trimoxazole to prevent opportunistic infections that may hasten the onset of serious disease. The model assumptions were informed by published evidence and expert opinion; rates of progression to serious disease were inferred from mortality of infected and uninfected children of HIV-infected mothers; and mortality among children treated with ART was based on a study of treated children in Abidjan. To allow widespread use the model has been developed using the Excel spreadsheet software.

RESULTS

With South Africa as a hypothetical example, published antenatal prevalence and demographic data, and assuming PMTCT coverage with single dose nevirapine of 11%, all exposed and infected children receive co-trimoxazole, and various infant feeding policy scenarios, estimated numbers of children eligible for ART are presented.

CONCLUSIONS

This model is easy to implement and flexible and can be used in ART programmes at national and local level.

Ethical issues in the NIMH Collaborative HIV/STD Prevention Trial

OBJECTIVE

To develop decision rules regarding key ethical dimensions in scientific protocols for the National Institute for Mental Health (NIMH) Collaborative HIV/STD Prevention Trial taking place in five countries (China, India, Peru, Russia, and Zimbabwe).

DESIGN

Countries had HIV rates from 27 to 0.1%, the standard of care varied from access to antiretroviral drugs to no availability, and the reporting of sexually transmitted diseases (STD) to government agencies was mandatory in some countries and not in others. These variations presented challenges when developing decision rules that could be uniformly adopted across countries and simultaneously follow the ethical principles of beneficence, respect, and justice.

METHODS

We used several strategies to identify and resolve ethical dilemmas for this international HIV prevention trial. First, we identified key principles, especially those derived for clinical therapeutic, biomedical preventive, or device trials. We convened a 'workgroup on protecting human participants' and charged them with identifying and implementing optimal procedures for ensuring the ethical and equitable treatment of participants and making recommendations to minimize physical, psychological, and social harm to the participants. Each site had a community advisory board, essential in identifying local ethical issues and possible resolutions to them. The NIMH established a data safety and monitoring board with ultimate responsibility for adjudicating ethical dilemmas and decisions. The protocols were deliberated thoroughly by the Trial steering committee, and approved by nine United States and five in-country institutional review boards.

RESULTS

We summarize the decision rules adopted to resolve the ethical dilemmas identified. Especially important were the translation of clinical trials principles for a behavioral intervention trial, strategies for ensuring confidentiality and informed consent, dilemmas relating to partner notification of sexually transmitted infections including HIV, minimizing the risks of social harm, establishing community partnerships, ensuring equity among United States and in-country principal investigators, and building capacity for additional research.

CONCLUSION

We document our processes and decisions, and their underlying rationales, and hope they contribute to the development of further thinking and practice regarding the ethics of social and behavioral HIV and STD prevention trials in resource-poor settings.

Prevention of Mother-to-Child Transmission of HIV-What Next?

Mother-to-child transmission (MTCT) of the human immunodeficiency virus (HIV) is a global problem. HIV can be transmitted from mother-to-child at various stages of pregnancy including in utero, intrapartum and during breastfeeding. A number of interventions have, therefore, been aimed at effectively providing alternatives to breastfeeding and limiting the risk of newborn infection during delivery, by using caesarian section as the mode of delivery and administering antiretroviral (ARV) drugs prepartum and peripartum. However, these approaches are not always possible in developing countries and the use of ARV drugs, in particular nevirapine, zidovudine and zidovudine/lamivudine, have been investigated in both developing countries and developed countries. The studies have involved the administration of various ARV prophylaxis regimens to HIV-infected pregnant women perinatally, either as monotherapy or in various combinations. In some studies, infants have also received ARV prophylaxis. Although studies have enrolled different populations and utilized various ARV drugs and regimens, encouraging reductions in the MTCT rates have been reported. These interventions have raised concerns regarding the development of ARV-resistant HIV strains. Mutations that confer resistance to nevirapine have been detected in pregnant women who received this drug, but the emergence of these mutations was not associated with an increased risk of transmission of HIV-1 to their infants. Studies are ongoing to determine if the presence of these mutations has implications for the subsequent administration of nevirapine, either to prevent MTCT of HIV-1 or for the mother's own health. Effective interventions that can reduce MTCT of HIV are now available worldwide. However, a number of issues remain to be resolved, particularly methods to reduce the transmission of the virus during breastfeeding and to deliver effective treatment for the mothers' own HIV infection.

Child survival in relation to mother's HIV infection and survival: evidence from a Ugandan cohort study

OBJECTIVE

To analyse the contribution of maternal survival and HIV status to child (under-5 years) mortality in a rural population cohort in South-west Uganda.

METHODS

Approximately 10 000 people residing in 15 neighbouring villages were followed between 1989 and 2000 using annual censuses and serological surveys to collect data on births, deaths, and adult HIV serostatus. Mother-child records were linked, child mortality risks (per 1000 births) and hazard ratios (HRs) for child mortality according to maternal HIV serostatus were computed, allowing for time-varying covariates.

RESULTS

A total of 3727 children were born, of whom 415 died during 14 110 child years of follow-up. Mother's HIV status at birth was ascertained unambiguously for 3004 children, of whom 218 were born to HIV-positive mothers. Infant mortality risk was higher for HIV seropositive than seronegative mothers (225 versus 53) as was child mortality risk (313 versus 114). Child mortality risk was also higher for mothers who died (571) than for surviving mothers (128). After controlling for child's age and sex, independent predictors of mortality in children were: mother's terminal illness or death (HR = 3.8); mother being HIV positive (HR = 3.2); child being a twin (HR = 2.0); teenage motherhood (HR = 1.7) and maternal absence (HR = 1.7).

CONCLUSION

Maternal survival and HIV status are strong predictors of child survival. The higher mortality in HIV-infected women compounds mortality risks for their children, regardless of children's HIV status. Programmes aimed at the welfare of children should take into account the independent effect of mothers' HIV and vital status.

Postnatal transmission of HIV-1 after a maternal short-course zidovudine peripartum regimen in West Africa

BACKGROUND

To assess the postnatal transmission (PT) risk of HIV-1 after a maternal short-course zidovudine regimen in a breastfeeding population.

METHODS

Data were pooled from two trials: ANRS 049a DITRAME (Abidjan, Côte d'Ivoire and Bobo-Dioulasso, Burkina-Faso) and RETROCI (Abidjan). Consenting HIV-1 seropositive women were randomized at 36-38 weeks' gestation between September 1995 and February 1998, to receive oral zidovudine or placebo: one tablet twice daily until delivery, and in DITRAME only, for 7 more days. A PT case was infection in a child with a negative HIV-1 PCR at age >/= 30 days who later became infected as defined by a positive HIV-1 PCR, or if aged >/= 15 months, a positive HIV serology. Cumulative risks (CR) of PT were computed using a competing risk approach with weaning as a competing event.

FINDINGS

At age 24 months, CR for PT were similar in the zidovudine (9.8%, n = 254) and placebo groups (9.1%, n = 225). In a multivariate model of PT risk factors, the treatment effect was not significant, maternal CD4 cell count < 500 x 10(6)/l at entry tripled the hazard compared to women with CD4 cell counts >/= 500 x 10(6)/l [hazard ratio (HR), 3.14; 95% confidence interval (CI), 1.31-7.49] as well as an increased maternal plasma viral load at entry (HR, 2.65 for 1 log(10) increase; CI, 1.75-4.00).

INTERPRETATION

PT occurred at a similar rate between arms and therefore reduced the long-term overall efficacy of this peripartum zidovudine regimen at age 24 months. The higher risk of PT among women with low CD4 cell count emphasizes the importance of identifying interventions to prevent PT for these women.

Antenatal and perinatal strategies to prevent mother-to-child transmission of HIV infection

Mother-to-child transmission (MTCT) is the dominant mode of acquisition of HIV infection for children. Each day an estimated 1600 children born to HIV-infected mothers become infected, 1500 of whom are in sub-Saharan Africa. Mother-to-child transmission can occur before, during and after delivery; overall rates of MTCT range from 15 to 35%. Risk factors for MTCT include maternal viral load levels, vaginal delivery, prematurity and breastfeeding. Approaches to reduce the risk of MTCT include reduction of maternal viral load through antiretroviral prophylaxis, avoidance of exposure through birth canal cleansing or elective caesarean section delivery and refraining from breastfeeding, and boosting the host immune system through nutritional supplementation or immunization. Substantial reductions in the risk of MTCT can be achieved with antiretroviral prophylaxis during pregnancy, delivery and in the neonatal period, both in settings with and without breastfeeding. Elective caesarean section independently decreases the risk, but is not a safe and feasible option in most high prevalence areas. Birth canal cleansing with chlorhexidine does not reduce the rate overall, but may be beneficial in a subgroup of women with prolonged duration of ruptured membranes. Micronutrient supplementation, including vitamin A, does not reduce MTCT of HIV, but may improve pregnancy outcome generally.

Children orphaned by AIDS: a global perspective

Internationally, the orphan crisis caused by the human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) pandemic remains a serious issue with long-term social consequences. At the end of 2001, an estimated 14 million children worldwide had lost their mother or both parents to AIDS or related causes. Sub-Saharan Africa is the most severely affected, accounting for more than 80 percent of those orphaned as a result of AIDS. Without the care of parents or an appointed caregiver, children are likely to face extraordinary risks of malnutrition, poor health, inadequate schooling, migration, homelessness, and abuse. Strengthening existing family and community capacity to assist orphans in Africa should be the first priority. Community support must be coupled with support for education for orphans. Combining local and international responses to deliver protection and services to all orphans and vulnerable children is critical. In addition, saving the lives of parents through access to antiretroviral therapies in resource-poor countries in conjunction with bold support for alleviation of poverty and education must be an integral part of the global response to the orphan crisis in sub-Saharan Africa.

Field acceptability and effectiveness of the routine utilization of zidovudine to reduce mother-to-child transmission of HIV-1 in West Africa

OBJECTIVE

To ascertain the field acceptability and effectiveness of the routine utilization of zidovudine in reducing mother-to-child transmission (MTCT) of HIV in breastfed children after a randomized clinical trial demonstrated its efficacy in Côte d'Ivoire and Burkina Faso.

METHODS

Pregnant women aged 18 years or older, who had confirmed HIV-1 infection, haemoglobinemia greater than 7 g/dl were enrolled in an open label cohort at 36-38 weeks' gestation to receive an oral short course of zidovudine. Paediatric HIV infection was defined as a positive HIV-1 polymerase chain reaction, or if aged 15 months or older, a positive HIV serology.

RESULTS

The acceptability of HIV pretest counselling was significantly higher in the cohort (90.3%) than in the trial (83.7%) (P < 0.001), but the return rate for HIV test results and for inclusion was low. A similar proportion of women accepted starting zidovudine in the cohort, 30.4% compared with 27.3% in the trial (P = 0.13). The proportions of women who took more than 80% of the expected zidovudine regimen were 81.8% before labour, 86.7% during labour, and 88.1% during the postpartum period, compared with those observed during the trial, 78.1, 81.1, and 85%, respectively. The MTCT probability at age 15 months was 19.6% in the cohort (n = 185) versus 21.2% in the trial (P = 0.52).

CONCLUSION

The major drawback with the implementation of a short zidovudine regimen to reduce MTCT is HIV counselling and testing procedures. For women who consent, zidovudine is well accepted and efficacious under routine circumstances.

15 Month follow up of African children following vaginal cleansing with benzalkonium chloride of their HIV infected mothers during late pregnancy and delivery

OBJECTIVES

To study mother to child HIV-1 transmission (MTCT) and infant mortality following benzalkonium chloride (BC) disinfection.

METHODS

A randomised, double blind phase II placebo controlled trial. Women testing positive for HIV-1 infection in prenatal care units in Abidjan, Côte d'Ivoire, and Bobo-Dioulasso, Burkina Faso, from November 1996 to April 1997 were eligible, with their informed consent. Women self administered daily a vaginal suppository of 1% BC (53) or matched placebo (54) from 36 weeks of pregnancy, plus a single dose during labour. The neonate was bathed with 1% BC solution or placebo within 30 minutes after birth. MTCT rate was assessed based on repeated polymerase chain reaction (PCR) and serology results. For the present analysis, children were followed up to 15 months.

RESULTS

A total of 107 women were enrolled. Of 103 eligible liveborn children, 23 were HIV infected, 75 uninfected, and five of indeterminate status. MTCT transmission rate was 24.2% overall (95% confidence interval (CI): 14.3% to 30.4%). On an intent to treat basis, the transmission rate did not differ between the two groups (23.5%, CI 13.8 to 38.5, in the BC group and 24.8%, CI 15.0 to 39.6, in the placebo group at 15 months). Similarly, there was no difference in mortality at 15 months (22.9%, CI 13.7 to 36.9, in the BC group and 16.5%, CI 9.0 to 29.4, in the placebo group).

CONCLUSION

This analysis failed to suggest any benefit of BC disinfection on mother to child HIV transmission or perinatal and infant mortality.

HIV-1/AIDS and maternal and child health in Africa

Every day, 1900 children acquire HIV-1 infection from their mother in Africa. The 25-45% risk of mother-to-child transmission can be reduced in several ways: prevention of sexual transmission for women of child-bearing age, access to HIV-1 testing, reduction of unwanted pregnancies by education of HIV-1-infected women, and antiretroviral-based prevention. All antiretroviral regimens of proven efficacy can be used in a minimum package of care for HIV-1-infected pregnant women. At present, programmes in 13 countries reach less than 3% of HIV-1-infected African women. 35-59% of African children infected with HIV-1 die by their second birthday. Infectious complications are preventable by primary prophylaxis with co-trimoxazole. A rapid scaling-up and comprehensive continuum of care is needed for all members of affected families, including access to antiretroviral treatment and community-based responses to the increasing number of orphans. Prevention of mother-to-child transmission should become a universal standard of care in Africa, and research should continue to reduce the transmission risk to well below 5%.

Twenty-four month efficacy of a maternal short-course zidovudine regimen to prevent mother-to-child transmission of HIV-1 in West Africa

OBJECTIVE

To assess the 24 month efficacy of a maternal short-course zidovudine regimen to prevent mother-to-child transmission (MTCT) of HIV-1 in a breastfeeding population in West Africa.

METHODS

Data were pooled from two clinical trials: DITRAME-ANRS049a conducted in Abidjan, Côte d'Ivoire and Bobo-Dioulasso, Burkina-Faso and RETRO-CI, conducted in Abidjan. Between September 1995 and February 1998, consenting HIV-1-seropositive women were randomly assigned to receive zidovudine (300 mg) or placebo: one tablet twice daily from 36-38 weeks' gestation until delivery, then in DITRAME only, for 7 more days. Paediatric HIV-1 infection was defined as a positive HIV-1 polymerase chain reaction, or if aged > or =15 months, a positive HIV-1 serology. Cumulative risks (CR) of infection were estimated using a competing risk approach with weaning as a competing event.

RESULTS

Among 662 live-born children, 641 had at least one HIV-1 test. All but 12 children were breastfed. At 24 months, overall CR of MTCT were 0.225 in the zidovudine and 0.302 in the placebo group, a 26% significant reduction. Among children born to women with CD4 cell counts < 500/ml at enrollment, CR of MTCT were similar, 0.396 in the zidovudine and 0.413 in the placebo group. Among children born to women with CD4 cell counts > or =500/ml, CR of MTCT were 0.091 in the zidovudine and 0.220 in the placebo group, a significant 59% reduction.

CONCLUSION

A maternal short-course zidovudine regimen reduces MTCT of HIV-1 at age 24 months, despite prolonged breastfeeding. However, efficacy was observed only among women with CD4 cell counts > or =500/ml. New interventions should be considered to prevent MTCT, especially for African women with advanced HIV-1 immunodeficiency.

Ensuring a public health impact of programs to reduce HIV transmission from mothers to infants: the place of voluntary counseling and testing

Since 1999, many African governments have launched programs to offer short-course antiretroviral drug regimens to reduce mother-to child transmission of HIV. HIV testing in prenatal care is the gateway to these antiretroviral regimens. Pilot projects in Africa show an uptake of antiretroviral drugs in 8% to 50% of pregnant women presumed to be HIV infected; often, a minority of eligible women in care received these regimens. Use of lay counselors and rapid onsite HIV testing may alleviate health service barriers. Community education to promote voluntary counseling and testing, which involves men, is the long-term solution. In the short term, possibilities to enhance delivery of an effective intervention include group pretest counseling, universal offer of testing with women having the right to "opt out," universal treatment (mass treatment for those whose HIV status is not determined by voluntary counseling and testing), universal testing with women having the right to "opt out" of learning their test results, and mass treatment for all without testing.

Estimating the efficacy of interventions to prevent mother-to-child transmission of HIV in breast-feeding populations: development of a consensus methodology

Postnatal transmission of HIV through breast milk complicates both the design of effective interventions to prevent mother-to-child transmission of HIV (PMTCT) and their evaluation. Estimated long-term efficacy in five African trials (four with peri-partum antiretrovirals and one with artificial feeding) varied from 25 to 50 per cent. This variation may be due, at least in part, to differences in analytical methodology. To facilitate direct comparison between trials, a methodological consensus approach to the analysis and presentation of the results of PMTCT trials was developed. The initial methodology used and results presented from African trials with available long-term efficacy data were reviewed during a workshop in Bordeaux, France, in September 2000. A consensus approach for evaluating efficacy applicable across PMTCT studies was developed. There are four typical situations defined by duration of follow-up (short versus long), and the available demographic (vital status) and biological data (single versus repeat HIV testing). Efficacy can be assessed from the risk of infection directly or from HIV-free survival by combining infection and death as a single endpoint. Studies should report results in a standardized format including infection, weaning, mortality and loss to follow-up. New statistical methods that account for the unknown date when a child would first test positive for HIV, for weaning as a competing risk for HIV infection, and for increased risk of death among HIV-infected children should be used in analysing data from PMTCT studies with repeat HIV testing. All estimates should be reported with confidence intervals. This standardized methodology that allows direct comparison between studies is now being applied to four randomized clinical trials.

Sexual and reproductive life of women informed of their HIV seropositivity: a prospective cohort study in Burkina Faso

BACKGROUND

In the context of the DITRAME-ANRS 049 research program that evaluated interventions aimed at reducing mother-to-child transmission of HIV (MTCT) in Bobo-Dioulasso (Burkina Faso), Voluntary HIV counseling and testing (VCT) services were established for pregnant women. HIV-infected women were advised to disclose their HIV serostatus to their male partners who were also offered VCT, to use condoms to reduce sexual transmission, and to choose an effective contraception method to avoid unwanted pregnancies. This study aimed at assessing how HIV test results were shared with male sexual partners, the level of use of modern contraceptive methods, and the pregnancy incidence among these women informed of the risks surrounding sexual and reproductive health during HIV infection.

METHODS

From 1995 to 1999, a quarterly prospective follow-up of a cohort of HIV-positive women.

RESULTS

Overall, 306 HIV-positive women were monitored over an average period of 13.5 months following childbirth, accounting for a total of 389 person-years. The mean age at enrollment in the cohort was 25.1 (standard deviation, 5.2 years). In all, 18% of women informed their partners, 8% used condoms at each instance of sexual intercourse to avoid HIV transmission, and 39% started using hormonal contraception. A total of 48 pregnancies occurred after HIV infection was diagnosed, an incidence of 12.3 pregnancies per 100 person-years. Pregnancy incidence was 4 per 100 person-years in the first year of monitoring and this rose significantly to 18 per 100 person-years in the third year. The only predictor of the occurrence of a pregnancy after HIV diagnosis was the poor outcome of the previous pregnancy (stillbirth, infant death). Severe immunodeficiency and change in marital status were the only factors that prevented the occurrence of a pregnancy after HIV diagnosis.

CONCLUSION

Our study shows a poor rate of HIV test sharing and a poor use of contraceptive methods despite regular advice and counseling. Pregnancy incidence remained comparable with the pregnancy rate in the general population. To improve this situation, approaches for involving husbands or partners in VCT and prevention of MTCT interventions should be developed, evaluated, and implemented.

Early diagnosis of paediatric HIV-1 infection among African breast-fed children using a quantitative plasma HIV RNA assay

OBJECTIVE

To evaluate the performance of a quantitative plasma HIV-1 RNA assay for HIV infection diagnosis among African breast-fed children.

METHODS

Serial plasma specimens collected in the first week, at day 45-90, 6 months and 9-12 months of age from HIV-exposed children born to HIV-1-infected women enrolled in the DITRAME ANRS 049a perinatal intervention trial (Abidjan, Côte d'Ivoire) were tested for HIV-1 plasma RNA using a branched DNA (bDNA) assay. Sensitivity and specificity of this RNA test were assessed in comparison with a qualitative DNA polymerase chain reaction (PCR) performed on the same blood samples and allowing a reliable detection of the predominant subtype A.

RESULTS

Among 91 samples from 53 infected children which tested positive by DNA PCR, the sensitivity of the bDNA test was 100% [95% confidence interval (CI), 96.0-100.0] at < or = 8 days (n = 19), 6-12 weeks (n = 43), 6 months (n = 26), and 9-12 months (n = 3). The median plasma HIV-1 RNA viral load ranged from 242 000 copies/ml at < or = 8 days to more than 500 000 copies/ml at day 45-90 and at 6 months. Of 106 specimens from 106 uninfected children who were DNA PCR- negative at month 3 or 6 of age, HIV-1 RNA was undetectable in 103, yielding an overall specificity for the bDNA test of 97.2% (95% CI, 92.0-99.4). The viral load in the three remaining samples with false-positive results was low (410, 937 and 3752 copies/ml, respectively).

CONCLUSIONS

The quantitative bDNA assay appears a suitable tool for early, reliable and easy diagnosis of paediatric HIV-1 infection among a population of African breast-fed children.

18-Month mortality and perinatal exposure to zidovudine in West Africa

OBJECTIVES

To study mortality in African children born to HIV-1-infected mothers exposed peripartum to zidovudine.

METHODS

A randomized placebo-controlled trial in Abidjan and Bobo-Dioulasso. Pregnant women received either 300 mg zidovudine twice daily from 36-38 weeks' gestation, 600 mg during labour, and 300 mg twice daily for 7 days post-partum or a matching placebo. Determinants of mortality were studied up to 18 months, overall and among the infected children: treatment, centre, timing of infection, mother and child HIV disease.

RESULTS

There were 75 infant deaths among 407 live births. The risk of death at 18 months was 176/1000 in the zidovudine arm and 221 for placebo. Relative hazard (RH, zidovudine versus placebo) was 0.47 [95% confidence interval (CI) 0.2-1.0] up to 230 days of life. Maternal CD4 lymphocyte count < 200/mm3 (RH 2.92; CI 1.4-6.1) and child HIV-1 infection (RH 12.6; CI 6.6-24.3) increased mortality of all children born to HIV-1-infected mothers. There were 101 children infected (40 in the zidovudine group), and 51 died. Their 18 month probability of death was 590/1000 in the zidovudine group and 510 in the placebo group. Among infected children, maternal zidovudine reduced the risk of death on or before day 230 (RH 0.18; CI 0.1-0.5). Maternal CD4 lymphocyte count < 200/mm3 (RH 3.25; CI 1.3-8.4), maternal death (RH 9.65; CI 1.7-56.0), diagnosis of paediatric infection on or before day 12 (RH 18.1; CI 4.8-69.0) and between days 13 and 45 (RH 7.63; CI 2.0-29.5), clinical paediatric AIDS (RH 5.37; CI 2.3-12.7) were risk factors for death in HIV-1-infected children.

CONCLUSION

Mother-to-child transmission reduction by zidovudine is safe and beneficial to African children. The mortality of HIV-1-infected children is high. Peripartum maternal zidovudine exerts a protective effect for at least 8 months.

Preventing vertical HIV transmission in the year 2000: progress and prospects--a review

In the USA, progress in the ability to eliminate vertical HIV-1 transmission that was unthinkable just a few years ago has been virtually achieved with fewer than 200 new cases of infant HIV infection reported in 1999. Nevertheless, critical research questions as well as public health challenges remain. New infant HIV infections continue to occur among women who did not obtain prenatal care or who were not offered HIV testing during pregnancy and innovative approaches are needed to address these barriers. The CDC-funded Mother-Infant Rapid Intervention At Delivery (MIRIAD) Study in five US metropolitan areas is one such approach that will test the feasibility of offering rapid testing to women presenting late in pregnancy or at delivery with undocumented HIV status. In addition, further research addressing the role of the placenta in preventing or enhancing in utero HIV transmission is needed. Internationally, new clinical trial findings provide hope that a short course of antiretrovirals can substantially reduce vertical HIV-1 transmission in resource-poor settings in the developing world where most paediatric HIV infections occur. Future research will focus on the role of post-perinatal exposure prophylaxis with antiretrovirals administered to the infant and on the prevention of postnatal transmission of HIV-1 through breast milk while maintaining adequate nutrition. A major challenge is to translate trial results into a coordinated public health implementation plan in order to maximally reduce mother-to-child HIV-1 transmission worldwide.

Maternal plasma viral load, zidovudine and mother-to-child transmission of HIV-1 in Africa: DITRAME ANRS 049a trial

OBJECTIVE

To study the relationship between maternal plasma RNA levels and mother-to-child transmission (MTCT) of HIV-1 in African breastfed children.

DESIGN

Nested case-control study within a randomized trial assessing the efficacy of a short maternal zidovudine (ZDV) regimen to reduce MTCT.

METHODS

Eligible women received either 300 mg of ZDV twice a day until labour, 600 mg at the beginning of labour and 300 mg twice a day for 7 days post-partum or a placebo. The diagnosis of paediatric HIV-1 infection was based on PCR tests at days 1--8, 45, 90 and 180 then on serology performed at 3 monthl intervals. Plasma HIV-1 RNA was measured at inclusion and on day 8 after delivery for all women who did transmit HIV to their children (cases) using a Chiron branched DNA assay (sensitivity 50 copies/ml) and compared with women who did not transmit (two per case) matched for phase trial, treatment allocation and site.

RESULTS

At inclusion, mean log10 viral load was 4.6 among 55 transmitting mothers and 3.7 among 117 non transmitters (P = 0.0001). Among transmitters, the mean difference in log10 viral load between day 8 post-partum and inclusion was -0.13 in the ZDV group (n = 23) versus 0.27 in the placebo group (n = 32; P = 0.01); among non transmitters it was -0.35 for the ZDV group (n = 47) versus 0.27 in the placebo group (n = 70; P < 10(-4)). In multivariate logistic regression analysis, odds ratios for MTCT were 8.7 (95% confidence interval, 3.7-20.6) for 1 log(10) increase of maternal RNA at inclusion and 4.2 (95% confidence interval, 1.7--10.3) for 1 log(10) increase difference from inclusion to day 8 post-partum.

CONCLUSION

High maternal viral load at inclusion strongly predicts MTCT of HIV in Africa. A short ZDV treatment regimen decreases significantly maternal viral load from its pretreatment level.

Expedited human immunodeficiency virus testing of mothers and newborns with unknown HIV status at time of labor and delivery

New York State introduced the first statewide program in the U.S. of expedited HIV testing (48-hour turn-around results) of mothers with unknown HIV status at the time of labor or delivery and their newborns on August 1, 1999. We evaluated the results of this program during its first 5 months at Lincoln Medical and Mental Health Center (Lincoln Hospital) in the Bronx, New York. There were 1,274 total live birth deliveries between August 1 and December 31, 1999. The HIV infection status of 539 mothers (42.3%) was unknown to medical providers in the labor-delivery suite, either due to lack of testing during the current pregnancy or unavailability of HIV documentation at the time of delivery. During labor and delivery, a total of 462 (85.7%) mothers with unknown HIV status consented to expedited HIV testing (Single Use Diagnostic System for HIV-1 antibody or SUDS). The newborns of 77 mothers (14.3%) who did not consent were tested immediately after birth. Seventeen tested positive for HIV-1 antibody by the SUDS test. The results of 10 of these infants (58.8%) were subsequently confirmed positive for HIV-1 antibody by Western Blot analysis. This new rapid HIV testing program facilitated early diagnosis of these previously unknown HIV-exposed infants, although the low positive predictive value of the test in our community calls for careful communication of these results pending confirmation.

Mother-to-child transmission of drug-resistant HIV

Mother-to-child transmission of HIV-I is responsible for the infection of hundreds of thousands of infants every year. The use of prophylactic antiretroviral treatments has brought about a dramatic decrease in the risk of transmission. Nevertheless, vertical transmission can still occur. In some cases, the presence of drug-resistant HIV-I strains in the mother has been responsible for the failure of the prophylactic scheme. Moreover, these strains have also been detected in the newborn. The aim of this review is to provide updated information on mother-to-child transmission of drug-resistant HIV strains and to help guide treatment decisions during pregnancy.