Role of Chlamydia trachomatis in perinatal infection

The transmission of Chlamydia trachomatis from the infected cervix of a mother to the eye of an infant, with resultant inclusion conjunctivitis, was documented in humans and in primates 75 years ago by cytologic methods. With modern microbiologic methodology it is possible to quantitate this transmission. It is now known that 2%-24% (usually 7%-12%) of cervices are infected before delivery and that 18%-50% (usually 20%-25%) of infants born to culture-positive mothers develop conjunctivitis. In addition, nasopharyngeal infection occurs in 15%-20% of infants, and 3%-18% develop pneumonia due to C. trachomatis. Bronchiolitis and otitis media are less common infections. The consequence of rectal and vaginal colonization remains unknown, as does the significance of the increase in antibody titers against C. trachomatis throughout early childhood. Early studies suggesting that C. trachomatis was a prominent cause of postpartum endometritis and a cause of premature delivery have not been confirmed in larger prospective studies when mycoplasma species were simultaneously studied. A subset of mothers with active infection, as evidenced by IgM antibody against C. trachomatis, may have earlier delivery, but it is clear that evaluation of the contribution of C. trachomatis to maternal and fetal risk will require larger studies with evaluation of possible concurrent mycoplasmal infection.