Economic issues in the prevention of vertical transmission of HIV

In the absence of interventions, 20% of infants born to women infected with HIV acquire infection from their mother at or before delivery. A further 1 5% are infected through breast feeding. prenatal testing for HIV allows inf ected women to be reliably identified so that they can receive antiretrovir al therapy and, in countries with safe water supplies, be advised not to br east feed. These and other interventions can reduce the risk of transmissio n to 5% or less. Economic evaluations of prenatal testing for HIV are reviewed and compared in this article, and future research priorities outlined. These studies set the costs of testing and intervention against the averted lifetime costs o f paediatric infection, and generate estimates of the HIV prevalence thresh old above which there would be a net cost saving, or calculate the cost per life-year saved given a particular prevalence. In the developed world, pre natal testing has been adopted in many countries, and recent economic analy ses broadly support this. Future research is likely to focus on the increme ntal benefits of different antiretroviral regimens in lowering transmission rates still further, with or without elective caesarean section, and the p ossibility that some may lead to adverse effects in uninfected infants expo sed to them in utero. Some earlier assessments in resource-poor settings concluded that prenatal testing was unaffordable or of doubtful cost effectiveness. This negative c onclusion appears to be the result of very low estimates of the lifetime co sts of paediatric HIV infection, together with developed world conceptions of pre-test counselling. The demonstration that nevirapine reduces transmis sion risk at a low cost has transformed the outlook, and there is hope that antiretrovirals can act prophylactically to prevent infection of the boast -fed child. However, to achieve a sustained reduction in vertical transmiss ion there may be a need to evaluate the need for a strengthened infrastruct ure to deliver prenatal HIV testing and treatment, as well as programmes to reduce HIV incidence in adults.