Neonatal conjunctivitis at a Brazilian tertiary center: the current relevance of Chlamydia trachomatis.

Purpose: The microbiology pattern of neonatal conjunctivitis has changed over time, and the incidence of gonococcal conjunctivitis is almost nil. This study aimed to determine the etiology of neonatal conjunctivitis cases referred to a tertiary health center in Brazil.

Methods: From 2017 to 2020, conjunctival swabs were taken from neonates with clinical signs of conjunctivitis and tested with bacterial culture and polymerase chain reaction for Neisseria gonorrhoeae and Chlamydia trachomatis.

Results: A total of 51 neonates were included in the 3-year study. Chlamydial conjunctivitis was diagnosed in 39 (76.5%) patients, and microbial growth was detected in 13 (25.5%) patients. The most isolated bacterium was Staphylococcus epidermidis (n=6, 11.8%), followed by other coagulase-negative Staphylococcus species (n=4, 7.8%) and S. aureus (n=2, 3.9%). One S. aureus isolate was resistant to oxacillin. There were no cases of gonococcal conjunctivitis. Ten (19.6%) patients showed polymerase chain reaction-negative C. trachomatis and negative bacterial culture test results.

Conclusion: Findings show that C. trachomatis is the most common pathogen causing neonatal conjunctivitis. The high prevalence of C. trachomatis infection highlights the importance of screening and treating pregnant woman.