Acute HIV infection among pregnant women in Malawi.

Acute HIV infection among pregnant women in Malawi.

There are limited data on acute HIV infection prevalence during pregnancy. Malawian pregnant women admitted in the third trimester and meeting eligibility criteria underwent dual HIV rapid antibody testing. Acute HIV infection prevalence was retrospectively detected through HIV RNA pooling of seronegative plasma. Among 3,825 pregnant women screened, dual HIV rapid testing indicated that 30.2% were HIV positive, 69.7% were HIV negative, and 0.1% were indeterminate. Sensitivity and specificity of dual rapid testing was 99.0% and 98.7%, respectively. Of 2,666 seronegative specimens, 2,327 had samples available for HIV RNA pooling; 5 women (0.21%) (95% confidence interval, 0.03-0.40%) had acute HIV infection with a median peripartum viral load of 1,324,766 copies/mL. Pregnant women are at risk for acute HIV infection, warranting counselling of all women and their sexual partners about incident HIV during pregnancy. Dual HIV rapid tests have high sensitivity and specificity. HIV testing should be repeated in the third trimester and/or at delivery.

Editors’ note: The highest viral loads are observed in the blood and in the genital tract during the first few weeks of HIV infection, known as acute HIV infection. When a pregnant woman acquires HIV infection, viral loads soar in the ramp-up phase of viraemia with the result that transmission to the foetus during pregnancy or delivery increases with each 1 log increase in viral load. In this study, the median viral load found in these newly infected pregnant women was 1.3 million copies/mL. Obviously, preventing HIV acquisition during pregnancy should be an overarching objective, possibly with couple counselling appealing to fathers’ desires for healthy children. But early detection of infection using pooled testing for RNA, even before seroconversion (antibody detection), might permit early intervention with triple drug antiretroviral prophylaxis to prevent mother-to-child transmission. Early days still but, in the meantime, repeat antibody testing at delivery may find women who have become infected during pregnancy and need antiretroviral prophylaxis/treatment for their babies and possibly themselves.