The feasibility of preventing mother-to-child transmission of HIV using peer counselors in Zimbabwe

Zimbabwe, a Southern African country with a population of approximately 12 million people, has one of the highest HIV prevalence rates in the world [1]. In 2003, an estimated 1.8 million individuals were living with HIV/AIDS in Zimbabwe, over half of whom were women [2]. Primary HIV infection in women of reproductive age fuels the perinatal HIV epidemic. Recent estimates indicate that 23.4% of pregnant women attending antenatal clinics in Zimbabwe are HIV seropositive [1]. Without any intervention, an estimated 50,000 infants acquire infection from their mothers annually in Zimbabwe [3]. In recent years, several clinical trials have demonstrated the efficacy of simpler and less expensive short regimens of zidovudine (ZDV), single-dose nevirapine (NVPsd), ZDV/lamivudine (3TC) or ZDV/NVPsd in preventing mother to child HIV transmission (PMTCT) in sub Saharan Africa [4–7]. However, implementation of PMTCT interventions on a large scale in resource-limited settings remains a formidable challenge [8–14].

In 1998, the Zimbabwe AIDS Prevention Project (ZAPP) was the first site in the country to successfully implement a pilot PMTCT project using community volunteers in Chitungwiza, a high density periurban community with a population of 1.5 million [15]. Routine antenatal services in Chitungwiza are provided by 4 municipal clinics, where approximately 10,000 deliveries occur annually. In Zimbabwe, 99% of women breastfeed and formula feeding is not feasible, or affordable or culturally acceptable in most settings. In 2000, the Zimbabwe Ministry of Health and Child Welfare (MOHCW) established national policy guidelines and implementation plan for PMTCT [16]. In 2002, with funding from the Elizabeth Glaser Pediatric AIDS Foundation, the ZAPP-Call-to Action (CTA) project collaborated with the MOHCW and Chitungwiza Health Department (CHD) to implement a NVP-based PMTCT program in Chitungwiza. The present report describes our experience in integrating a PMTCT program into routine prenatal care in urban Zimbabwe, highlighting the operational challenges and lessons learnt during implementation.

This report demonstrates the feasibility of implementing a NVP-based PMTCT program using peer counselors in a periurban antenatal clinic setting in Zimbabwe. The peer counselors were HIV-infected women who had previously participated in a ZDV-based PMTCT program at our site. In this country, economic hardships and political instability have seriously undermined the maternal and child health services [20]. Despite the high nursing staff attrition rate, severe shortage of human resources staff, and weak health care system at our clinics, PMTCT services delivered by peer counselors were feasible, acceptable and sustainable.

In addition to providing health education and HIV counseling, the peer counselors acted as "mentors" to newly diagnosed HIV-infected mothers providing ongoing counseling and support, which involved several complex issues such as coping, bereavement, domestic abuse, spousal abandonment, discordant test results, family planning, and negotiating safe sex. The counselors also provided infant feeding counseling, referred clients for psychosocial support, facilitated support group meetings, and followed mothers and infants from birth through 18 months in the clinics.

A close working relationship between the project staff, the municipality staff from the Chitungwiza health department, and the ministry of health and child welfare of Zimbabwe ensured smooth functioning of the program. Our findings are important for policy makers because the incorporation of peer counselors in PMTCT program could be replicated in other resource-limited settings. Delivery of PMTCT services using trained peer counselors is now routinely implemented at several urban and rural sites in Zimbabwe [1, 12]. Adequate staffing and on-site training is critical to maintain the high quality of counseling services [12].

The prevalence of HIV infection in Zimbabwe is one of the highest in the world. In the present study, 19% of women were HIV-infected; this finding is consistent with recent trends in HIV prevalence in Zimbabwe [1]. During the study period, antenatal HIV testing was routinely performed after individual pre-test counseling, with clients actively choosing whether to be tested (i.e., an "opt-in" approach or client-initiated testing). It is concerning that only 56% of pregnant women at our site opted for HIV testing. Qualitative data from focus group discussions among antenatal women have revealed a number of barriers to VCT. Reasons most often cited by women in our clinics who refuse testing include the need to consult their husbands/partners, fear of stigma and domestic violence upon disclosure to partner, lack of availability of highly active antiretroviral therapy (HAART), and denial of HIV [21]. These social and health service barriers have been identified in other settings [22, 23]. Therefore, new innovative approaches to antenatal HIV testing should be considered.

Provider-initiated routine HIV testing (i.e., an "opt-out" approach) is currently the standard of care for pregnant women in resource-rich nations [24]. Recently, successful introduction of routine opt-out antenatal HIV testing has been reported from Botswana and Kenya. [25–27]. A recent survey conducted in two rural districts of Zimbabwe found that routine antenatal HIV testing is acceptable to pregnant women [28]. A pilot project at our urban PMTCT site evaluated the feasibility, acceptability, and impact of routine offer of antenatal (opt-out approach) HIV testing in 2005. Routine antenatal HIV testing resulted in significant increases in testing and PMTCT services without measurable adverse consequences [29].

Low return rate for HIV-positive test results has been a major problem in many PMTCT programs in sub Saharan Africa [9, 13, 14]. In our study, the rate of collection of positive test results among women was 92%. Use of rapid on-site HIV testing with same-day availability of test results may partly explain the high return rates. Similar findings have been reported in other PMTCT programs in sub Saharan Africa [30, 31].

In this study, the overall maternal/infant uptake of NVPsd was poor because of the mobile population and loss to follow-up at each stage of the PMTCT cascade of services. Dispensing NVPsd to HIV-infected pregnant mothers at the time of diagnosis may improve access to antiretroviral prophylaxis in our setting. The high uptake of NVPsd among the documented HIV-positive deliveries in the clinics is encouraging. However, it is important to note that the HIV-infected mothers who delivered in our clinics represent a highly selected group with different health seeking behaviors from those women who delivered elsewhere.

In our study, the proportion of male partners accepting HIV testing was very low. This finding is not surprising because none of the PMTCT interventions targeted men specifically. Low participation of male partners has been reported in rural PMTCT program as well [12]. Male partner involvement in conjunction with enhanced community mobilization and IEC activities geared towards HIV prevention, non discrimination and non stigmatization may improve VCT uptake and PMTCT interventions [32]. Innovative approaches to promote male involvement are urgently needed. HIV-infected women often don't disclose their serostatus to their husbands/partners due to fear of stigma, violence, abandonment or divorce [33, 34]. A recent report from Zambia showed that antenatal couple VCT did not increase the risk of adverse social events associated with HIV disclosure [35]. Another report from Kenya showed that antenatal couple counseling increased uptake of sdNVP and formula feeding [36]. Strategies to enhance antenatal VCT coverage and uptake of PMTCT interventions through gender-sensitive programs should be developed.

Psychosocial support with special attention to disclosure issues is a critical component of PMTCT program. Two-thirds of HIV-infected women in our program joined support groups. Experiences on PSS from urban and rural PMTCT programs in Zimbabwe have led to development of national PSS guidelines which will be disseminated to health care workers throughout the country for widespread implementation.

In the present study, 59% HIV-infected women opted for contraceptive options in the postpartum period. Integrating family planning with PMTCT programs is crucial in sub Saharan Africa, where HIV seroprevalence and rates of unintended pregnancy are high [37].

In our program, the sdNVP regimen was used to prevent perinatal HIV transmission. Data from African trials indicate that addition of maternal intrapartum/neonatal sdNVP to short-course ZDV or ZDV-3TC may reduce perinatal HIV transmission rate to below 5%, approximately half the transmission rate that can be achieved by sdNVP [7, 38]. Pilot projects supported by donor funds has been implemented in Zimbabwe to evaluate the field acceptability and effectiveness of more efficacious antiretroviral regimens in PMTCT programs, in line with World Health Organization (WHO) guidelines [39]. Finally, despite effective PMTCT interventions, ongoing breastfeeding HIV transmission is a major public health issue [40].

Early diagnosis of HIV infection in exposed infants is critical to improve pediatric HIV/AIDS care in resource-limited countries [41]. However, the high cost of PCR testing, technical expertise needed for infant venesection, and other logistic issues have posed major obstacles at our site. Therefore, developing alternative low-cost laboratory methods for early infant HIV diagnosis remains a priority for Zimbabwe and other resource-poor settings. A prospective cohort study from South Africa has shown that HIV DNA PCR tests performed on dried blood spots from HIV-exposed infants at 6 weeks of age yields accurate results [42]. Another report from Zimbabwe suggests that the ultrasensitive p24 antigen assay is a useful diagnostic test for diagnosing HIV infection among infants less than 2 years with similar sensitivity and specificity as HIV RNA PCR [43].

Follow-up of HIV-exposed infants poses a tremendous challenge in resource-limited settings. Maternal/infant follow-up should be integrated within the existing MCH services. To address this challenge, a decentralized district approach is suggested in rural settings [12]. In addition, the child heath card has been recently revised by the MOH/CW with support from EGPAF and Centers for Disease Control and Prevention (CDC)-Zimbabwe to facilitate mother-infant follow-up at all antenatal clinics in Zimbabwe.

Antenatal clinics are a key entry point into HIV treatment and care, together with interventions to reduce mother-to-child transmission of HIV. In our program, 16% of HIV-infected women had evidence of WHO clinical stage III and IV disease. Access to HAART was limited at the time of the study. Strategies to scale up treatment access are urgently required in resource-limited settings to prevent mortality as well as transmission [44]. Recent reports from South Africa and Zambia showed that it is feasible to integrate HAART within antenatal care [45].

The current report has several limitations. First, the extremely mobile population in our urban setting, loss to follow up of HIV-infected women after the post-test counseling visit and subsequently during the postnatal period, and unavailability of early infant diagnosis makes it impossible to measure the precise coverage and impact of sdNVP intervention. Second, this is not a controlled study. Finally, the quantitative data presented from a large urban setting, which poses different challenges compared to similar PMTCT programs in rural settings.

Despite the severe shortage of human and economic resources encountered in our setting, it was feasible to implement a PMTCT program using peer counselors in urban Zimbabwe. Strong commitment from the Ministry of Health and the Chitungwiza Health Department, and financial and technical support from EGPAF and CDC-Zimbabwe contributed significantly to the success of the program.