Time to implement 9-month infant HIV testing in South Africa

South Africa (SA) is likely to meet the National Strategic Plan target of <2% mother-to-child HIV transmission at 6 weeks of age in 2015. Children infected with HIV after 6 weeks often remain undiagnosed because of poor implementation of post-weaning and final outcome 18-month HIV testing. The World Health Organization recommends a screening HIV rapid test (HRT) in HIV-exposed infants at the 9-month immunisation visit to exclude postnatal infection, with a confirmatory HIV polymerase chain reaction (PCR) test if the HRT is positive.

To evaluate the impact of substituting this recommendation for the post-weaning HIV testing recommended by SA guidelines.

Rates of seroreversion and probability of infection at 9 months of age were applied to a theoretical population of 100 HIV-exposed infants, uninfected at birth and breastfed for 1 year with antiretroviral prophylaxis. Nine scenarios were developed and the number of HIV PCRs saved compared with current guidelines was calculated.

Nine-month testing using the HRT reduced the number of follow-up PCR tests done in all scenarios by >50%, with differences ranging from 51% to 59% and 81% to 89% for low and high seroreversion rates, respectively.

Nine-month testing using HRT would increase identification and early treatment of HIV-infected infants, improve monitoring of postnatal transmission rates, and reduce the number of HIV PCR tests done with resultant cost saving. Training of healthcare workers implementing HRT would be required. Ongoing efforts to improve implementation and monitoring of testing at 9 and 18 months will be essential.