Mother-to-child transmission of Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis in HIV-infected pregnant women in South Africa.

Background: Sexually transmitted infections (STIs) can be transmitted from mother to neonate. We determined the frequency of mother-to-child transmission (MTCT) of , , and to the newborn nasopharynx.

Methods: This study was nested in a cohort study of etiologic testing versus syndromic management for STIs among pregnant women living with human immunodeficiency virus in South Africa. Mothers were tested for STIs using the GeneXpert platform within 60 days after delivery. Nasopharyngeal swabs were obtained from newborns of mothers with a positive STI test; these were then tested by Xpert® on the same day based on the maternal STI diagnosis.

Results: We tested nasopharyngeal swabs from 85 STI-exposed newborns; 74 (87%) were tested within 2 weeks after birth (median five; range 2-12 days). MTCT frequency of any STI was 30/74 (41%); 43% (23/53) for , 29% (2/7) for , and 24% (6/25) for . Also, 4/11 (36%) swabs obtained between 14 and 60 days after delivery tested positive for STI.

Conclusions: There was a high frequency of MTCT of STIs to the nasopharynx of newborns in our setting. The impact of nasopharyngeal colonization and the benefits of STI testing on newborn health remain to be determined.