Objective: To study temporal changes in HIV-1 seroreversion (change in reactivity of HIV serology from positive to negative) in uninfected infants born to HIV-1-infected mothers.
Methods: Secondary analysis of data from 3 cohort studies conducted in Malawi among infants born 1989 through 1991 (International Collaborative AIDS Research [ICAR]), 1993 through 1996 (HIV Network for Prevention Trials [HIVNET]), and 2000 through 2003 (nevirapine/zidovudine [NVAZ]). The proportion of children HIV seroreverting at ages 15, 18, and 21 months and the relative odds for seroreversion comparing infants born before 1997 to those born after 1999 were calculated.
Results: Included in this analysis were 635 infants from ICAR, 459 from HIVNET, and 1020 from NVAZ. During the study, there was a consistent trend of decrease in proportion of children seroreverting over time: highest during 1989 through 1991, intermediate during 1993 through 1996, and lowest during 2000 through 2003. Additionally, there was a strong association between seroreversion and year of birth (before 1997 vs. after 1999): adjusted relative odds 5.1 at 15 months, 8.2 at 18 months, and 11.2 at 21 months.
Conclusions: Age of seroreversion in HIV-1-exposed uninfected infants increased over time. Persistence of maternal HIV-1 antibodies could have implications on timing of infant HIV-1 diagnosis using serological diagnostic methods.