A Missed Target of Ocular Prophylaxis: Neonatal Chlamydia trachomatis

Introduction Neonatal conjunctivitis can be defined as an inflammation of the surface or covering of the eye that presents with eye discharge and hyperemia, which occurs within the first four weeks of life. The incidence of neonatal conjunctivitis ranges from 1.6% to 12% of all newborns [ 1 ]. The etiology is chemical, bacterial, or viral. Most infections are acquired during vaginal delivery; however, transmission can also occur during cesarean section in case of premature rupture of membranes [ 1 ] [ 2 ]. Although the incidence of Chlamydia trachomatis conjunctivitis is rare, it can develop in 20% to 50% of infants delivered vaginally to infected, untreated mothers [ 3 ]. Neonatal ocular prophylaxis does not prevent the incidence of chlamydia conjunctivitis. Infected eyes have mucopurulent discharge, ocular congestion, eyelid swelling, chemosis, and pseudomembrane formation on the palpebral conjunctiva. In addition, C. trachomatis may lead to pneumonia in addition to conjunctivitis. Neonatal chlamydial conjunctivitis may be treated with systemic erythromycin 50 mg/kg/day for 14 days or systemic azithromycin 20 mg/kg as a single daily dose for 3 days [ 4 ] [ 5 ]. The primary means of preventing neonatal chlamydial infection is screening and treatment of pregnant women. This case is notable for the rapid clinical progression of conjunctivitis despite early topical antibiotic administration, demonstrating that neonatal ocular prophylaxis is ineffective in preventing C. trachomatis infection and highlighting the limitations of current regional prophylaxis practices as well as the clinical importance of maternal screening and early microbiological confirmation. Publication History Received: 01 December 2025 Accepted after revision: 27 January 2026 Article published online: 16 February 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany