Chlamydia is the most common sexually transmitted bacterial infection worldwide, with approximately 131 million cases appearing annually.^1,2 Chlamydia can be passed from an infected mother to a newborn during delivery, and 30% to 50% of infants born to a mother with active infection develop neonatal conjunctivitis.³

A recent study suggests that while erythromycin at 50mg/kg per day for 14 days results in a higher percentage of cured neonatal chlamydial conjunctivitis cases than azithromycin at 20mg/kg per day, more data is needed to further compare both treatments.⁴

A team of Canadian researchers identified 12 studies that evaluated the effects of these oral antibiotics on nearly 300 neonates with chlamydial conjunctivitis. They found that the clinical and microbiological cure rates of using erythromycin were 96% and 97%, respectively. Adverse gastrointestinal effects only occurred in 14% of the neonates, the study notes. As for azithromycin, the researchers found that the microbiological cure rate was lower, at 60%, when given in a single dose and 86% when given in a three-day course.

Due to the risk of bias and the small subject pool, however, the study notes “the certainty of evidence is low to very low.”

In addition, compliance and risk of pyloric stenosis related to the use of both antibiotics for other neonatal infections factors into treatment recommendations, according to the authors. They conclude that further research is necessary.