There are several obstacles on the path to bringing the known efficacy of MTCT interventions to bear in a population. Dr Jeffrey Stringer, Associate Professor of Obstetrics and Gynaecology at the University of Alabama Birmingham, described problems with scaling up MTCT programmes in Zambia at the XIV International AIDS Conference today in Barcelona.
Dr Stringer has spent the past two years working with the Zambian government to develop a mother to child transmission prevention programme. He argued that the effectiveness of MTCT programmes needs to be assessed in terms of the population coverage: the total annual population of pregnant women with HIV, divided by the number of women who actually take treatment to prevent tramsission.
In the Zambian capital Lusaka, there were 45,000 institutionalised deliveries in 2001. With a known prevalence of around 29% in women of child bearing age, this translates into approximately 13,000 mothers with HIV infection giving birth in one year. Last year it was possible to offer HIV testing and nevirapine to 40% of mothers with HIV (around 5,200), of whom 64% accepted an HIV test. Of the mothers who were diagnosed with HIV, 74% actually took the nevirapine that was prescribed, giving a population coverage of 19% in a city that Dr Stringer described as a flagship for MTCT programmes.
A study conducted in Zambia by Dr Stringer’s group found that the offer of nevirapine therapy without testing resulted in a higher uptake, but only 61% of women took the drug, compared to 74% of women offered the drug as a result of testing HIV-positive (a statistically significant difference).
He suggested that cost-effectiveness of interventions may be improved by group pre-test counselling, by using cheaper and simpler testing algorithms (the combination of tests required to diagnose HIV infection) and by offering nevirapine without testing, especially where stigma is a major issue in a community.
Scaling up might also be made more affordable by diverting money from other health care interventions. Dr Stringer highlighted a recent study published in The Lancet (Villar, 2001), which showed that four antenatal visits were just as effective as a larger number in resource-limited settings. If the total number of antenatal visits could be reduced, he argued, personnel and space could be freed up to treat a larger number of HIV-positive mothers.
“Antenatal care [in resource-limited setting] often reflects industrialised world priorities and aims to prevesetting] often reflects industrialised world priorities and aims to prevent less serious health problems.” said Dr Stringer. He went on to point out that the burden of HIV-related infant mortality in the first few years of life is equal to the total burden of child mortality from all other causes in the first year of life in Zambia, a powerful argument for the diversion of resources to MTCT programmes.