The effect of Plasmodium falciparum malaria on peripheral and placental HIV-1 RNA concentrations in pregnant Malawian women

Abstract

To investigate the effect of placental Plasmodium falciparum malaria infection on peripheral and/or placental HIV-1 viral load. A cross-sectional study of HIV-infected pregnant women, with and without placental malaria, delivering at Queen Elizabeth Central Hospital in Malawi. Peripheral blood samples were collected from consenting women and tested for HIV. HIV-infected women received nevirapine at the onset of labor. At delivery, placental blood and tissue specimens were collected. HIV-1 RNA concentrations were measured in peripheral and placental plasma samples, and malaria infection was determined by placental histopathology. Of the 480 HIV-infected women enrolled, 304 had placental histopathology performed, of whom 74 (24.3%) had placental malaria. Compared with women without placental malaria, those with placental malaria had a 2.5-fold higher geometric mean peripheral HIV-1 RNA concentration (62 359 versus 24 814 copies/ml; P = 0.0007) and a 2.4-fold higher geometric mean placental HIV-1 RNA concentration (11 733 versus 4919 copies/ml; P = 0.008). In multivariate analyses, after adjusting for CD4 cell count and other covariates, placental malaria was associated with a 1.7-fold increase in geometric mean peripheral HIV-1 RNA concentration (47 747 versus 27 317 copies/ml; P = 0.02) and a 2.0-fold increase in geometric mean placental HIV-1 RNA concentration (9670 versus 4874 copies/ml; P = 0.03). Placental malaria infection is associated with an increase in peripheral and placental HIV-1 viral load, which might increase the risk of mother-to-child transmission of HIV.