Untreated sexually transmitted infections (STIs) in pregnancy such as Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) can have adverse effects on maternal and infant health. Recent availability of highly sensitive nucleic acid amplification tests (NAAT) allow for more accurate prevalence assessments. As part of NICHD HPTN 040, a multi-center clinical trial evaluating new infant treatment regimens for the prevention of intrapartum HIV mother-to-child transmission (MTCT), we evaluated the prevalence of these STIs and their association with HIV MTCT for the Americas cohort, which included Brazil, Argentina, and the U.S.
Urine samples from 799 HIV-positive pregnant women collected at the time of labor/delivery underwent CT and NG NAAT using GeneXpert® (Cepheid Inc., Sunnyvale, CA). Infant HIV infection was determined by HIV DNA PCR. Infants were not breastfed. Descriptive statistics were used to summarize results, and Fisher’s exact test was used to compare HIV MTCT between groups.
Of the 799 HIV-positive pregnant women, 146 (18.3%) had infections with either CT, NG, or both CT/NG. 134 women (16.8%) had CT alone or in combination, 24 (3.0%) had NG either alone or in combination, and 12 women (1.5%) had dual CT/NG infection. 67 women (8.4%) transmitted HIV to their infants. HIV MTCT in the CT-only group was 12.3% (15/122), 0% in the NG-only group (0/12), 25% (3/12) in the dual CT/NG group, and 7.5% (49/653) in the uninfected group (p <.001). Women co-infected with CT/NG were 3.1 times as likely to transmit HIV to their infants (RR: 3.1; 95% CI: 1.1, 8.4) than those without these infections.
HIV-positive pregnant women are at high risk for infection with CT and/or NG, which may impact HIV MTCT. NAATs may facilitate effective CT and NG diagnosis and should be routinely implemented for active screening and treatment.