How much paediatric HIV infection could be prevented by antenatal HIV testing

Objective - To estimate the reduction in the number of children infected with HIV that might be achieved by extending the provision ofvoluntary antenatal HIV test­ ing. This effect would be mediated by in­ creased numbers of women infected with HIV who receive an intervention to reduce the risk of vertical transmission (for ex­ ample, zidovudine or caesarean section delivery), who use an alternative to breast feeding, or whose pregnancy is ter­ minated. Setting - London, United Kingdom. Methods - Relevant data were derived from neonatal seroprevalence studies, ob­ stetric and paediatric reporting schemes, and review ofexternal information. Sensi­ tivity analyses were performed for certain parameters. Results - Of 106 000 births annually in London, an estimated 169 are to women infected with HIV whose infection is not currently recognised before pregnancy. An estimated 28-33 children born to these womenwill be infected. Precise prediction ofthe number ofpaediatric HIV infections that could be prevented is difficult because of uncertainty in certain factors, par­ ticularly the uptake of antenatal testing and the efficacy and acceptability of in­ terventions to reduce prenatal or perinatal transmission. H a testing programme de­ tected 70% of infected women, none of whom opted for a termination but all of whom exclusively bottle fed and received an intervention which halved the risk of transmission, about 12-16 (42-46%) pae­ diatric HIV infections would be prevented annually. Conclusions - The estimated cost of pre­ venting each paediatric infection is high, but this should be seen in the context of the lifetime health and social care costs for a child infected with HIV. The feasibility of selective testing should be considered when formulating policies on antenatal HIV testing. Programmes that are in­ troduced shouldbe audited to obtainbetter estimates of costs and benefits. (Journal of Mera2:35-40)