Zambia's HIV prevalence rates are among the highest in the world. While simple and cost-effective measures are now available to prevent mother-to-child transmission, implementation is not as straightforward as it may seem. Until recently, most nations in the developing world, including Zambia, have lacked the appropriate personnel, training, and infrastructure to deliver these interventions effectively on a scale commensurate with the huge burden of infection. The Lusaka Call-to-Action program has sought to build human resource and prevention capacity in the public sector so that every pregnant woman in the city has the opportunity to be counseled and tested for HIV and to receive anteretroviral prophylaxis if seropositive.
One of the most challenging components of the program has been to determine its true population coverage rate. In Lusaka, and indeed most of subSaharan Africa, pregnant women carry their antenatal records with them. Therefore, while it is straightforward to determine how many counseled women agree to testing, it is more difficult to know what proportion of eligible women are actually getting testing in the various communities served by each clinic. It is clear that the program does not succeed in counseling each and every woman, largely because of staffing and space limitations. In addition, while acceptance rates for testing are 72%, still more than one in five women decline HIV testing. With continued community mobilization and improved counseling skills of the nurses, it is anticipated that the proportion accepting testing will improve.
The most concerning observations are that only 57% of women who tested seropositive were documented as having taken possession of the NVP tablet to date, and that only 40% of infants born to program participants received NVP syrup. Many other studies have noted a similar attrition phenomenon [7
]. The number of women and infants receiving NVP should at any given time be lower than the number of identified HIV-infected mothers because of a ‘lag time’ between when women are tested and when they receive NVP. However, we suspect that a significant proportion of the women in our program are not returning to the clinic for receipt of NVP. In practice, this has been very difficult to document, since HIV testing in our setting is anonymous, and we cannot send clinic personnel into the community to locate and question those who elect not to return for care. In recently conducted focus groups with antenatal women, stigma, fear of partner abuse, fear of more rapid death once knowing ones' status, and not wanting to prevent their babies from getting HIV if there is no maternal treatment available were all reasons women gave for not testing and not taking NVP. Others have postulated similar reasons for refusal of testing, NVP or partner disclosure, such as stigma and fear of violence and desertion [8
]. We hope that generalized stigma-reduction messages in the target communities will, over time, work to mitigate program dropout. We also expect that, as perinatal prevention services and even treatment become more widely available, testing and medication adherence will improve. Finally, we hope that involvement of men in ongoing perinatal programs will help to increase the number of women and infants who are compliant with interventions to reduce mother-to-child transmission of HIV [10
]. We are currently exploring offering partner and couples counseling on weekends.
The costs reported here exceed by several times those estimated in published economic models, including our own [11
]. There are several potential reasons for this. First, the econometric models may have underestimated certain factors that are critical in real practice, such as the need for full-time coordinating staff, replacement drugs, fuel for vehicles, etc. Second, formal cost-effectiveness analysis would credit a program for averted medical care associated with prevented disease. Therefore, in order to compare the present report directly with prior models, one would have to estimate the cost savings to the medical system of the 190 infant HIV cases we believe have been prevented. Third, and probably most important, a major detriment to the cost effectiveness of our program is the considerable attrition of patients from the system [9
]. We may spend considerable resources counseling and identifying them only to have them disappear and not benefit from the intervention. Obviously, retention of patients represents a critical area for evaluation and improvement in our program. Progress in this area, coupled with third-party test kit and drug donations, will likely increase the cost-effectiveness of our program considerably.
Perhaps the single most important element of the program's initial success has been the strong commitment from the Lusaka District Health Management Board, which is now promoting ‘universal HIV counseling with optional testing’, similar to that increasingly common elsewhere [13
]. Despite the challenges we have experienced, the potential public health impact of a program like ours is enormous. Expanded voluntary counseling and testing, improved acceptance of HIV-infected persons, and the extensive community education that accompanies the program will likely provide benefit far beyond the infant lives saved with NVP therapy. Since the NVP component of the program has been uncomplicated and safe, [14
], we feel strongly that any facility that successfully offers voluntary counseling and testing to antenatal mothers should also offer prophylactic antiretroviral drugs such as NVP or short-course zidovudine. Early experience in Lusaka suggests that a large-scale, NVP-based perinatal HIV prevention program is feasible and sustainable, especially when drug and test kits are donated and start-up costs are provided. In the next year, we hope to be able to show that antiretroviral treatment services can be integrated into existing perinatal prophylaxis services. Toward that end, we have obtained funding to provide combination antiretroviral treatment to pregnant and postnatal mothers, fathers, and children with AIDS in one Lusaka District facility. Activities began in early 2003 through funding organized by the MTCT, plus a consortium at Columbia University [15
]. While we focus on increasing the coverage of our perinatal programs, we believe that finding ways to integrate antiretroviral therapy into these programs will become increasingly important.