Abstract
Objectives: To estimate HIV-1 incidence and cofactors for HIV-1 incidence during pregnancy and postpartum. Design: Retrospective study among women who were HIV seronegative during pregnancy. Methods: Mothers accompanying their infants for routine 6-week immunizations at 6 maternal child health clinics in Nairobi and Western Kenya were tested for HIV-1 after completing a questionnaire that included assessment of sociodemographics, obstetric history and HIV-1 risk perception. Results: Of 2,135 mothers who had tested HIV-1 seronegative antenatally, 2,035 (95.3%) accepted HIV-1 re-testing at 6 weeks postpartum. Of these, 53 (2.6%) were HIV-1 seropositive yielding an estimated HIV-1 incidence of 6.8 (95% CI: 5.1-8.8) per 100 woman-years). Mothers who seroconverted were more likely to be employed (45.3% vs 29.0%, p=0.01), married (96.2 vs 86.6%, p=0.04) and from a higher HIV-1 prevalence region (60.4% in Western Kenya vs 28.8% in Nairobi, p < 0.001). Among married women, those in polygamous relationship were significantly more likely to seroconvert (19.6% vs 6.7%, p < 0.001). In multivariate analysis, region and employment independently predicted seroconversion. Conclusions: Repeat HIV-1 testing in early postpartum was highly acceptable and resulted in detection of substantial HIV-1 incidence during pregnancy and postpartum period. Within prevention of mother-to-child HIV-1 transmission programs strategic approaches to prevent maternal HIV-1 acquisition during pregnancy are urgently needed.
Keywords: Seroconversion, pregnancy, incidence, sub Saharan Africa, risk factors, heterosexual transmission, HIV-1 Incidence, Postpartum, HIV seronegative, HIV-1, PMTCT, CCR5 co-receptor expression, Maternal and Child Health, antenatal care, Abbott Determine test kit, HIV ELISA test, Comprehensive Care Clinics, Chi square, Fisher's exact test, polygamous relationship, HIV-1 testing, prenatal HIV prevention, HIV-seronegative mothers, sexually transmitted diseases, HIV-1 Vaccine Efficacy Trials, monogamy, Kenya National Bureau, ICF Macro, preventing perinatal transmission