Randomised equivalency trial comparing 2.5% povidone-iodine eye drops and ophthalmic chloramphenicol for preventing neonatal conjunctivitis in a trachoma endemic area in southern Mexico

Aim: To evaluate the effectiveness of 2.5% povidone-iodine eye drops ( PIED) compared with ophthalmic chloramphenicol (OC) for preventing neonatal conjunctivitis. Methods: 2004 neonates were enrolled from three rural hospitals in a trachoma endemic area. They were randomly assigned to receive either PIED (n=1024) or OC (n= 974). Infectious conjunctivitis was confirmed by laboratory methods, including specific search for Chlamydia trachomatis by polymerase chain reaction assay. Results: During the first 48 hours after birth, PIED and OC had similar efficacy against bacterial conjunctivitis (95% confidence interval (CI), -0.031 to -0.004; p = 0.01); from day 3 to day 15, PIED was 6% less effective than OC ( 95% CI, -0.058 to -0.006; p = 0.01); after day 16 there was no significant difference between the groups ( 95% CI, -0.022 to 0.041; p = 0.57). However, the risk of C trachomatis conjunctivitis was increased in neonates receiving PIED prophylaxis ( relative risk = 1.99 ( 95% CI, 1.07 to 3.71), log-rank p = 0.029). Ocular side effects were rare and self limiting in both groups ( p = 0.223). Conclusions: PIED seems to increase the risk of acquiring chlamydial conjunctivitis in neonates. Additional measures are required to prevent mother to fetus transmission of chlamydial infection during pregnancy, delivery, and after birth.