The rate of trachoma, or ocular chlamydia, among children living in hyperendemic areas can be stalled with annual or biannual mass azithromycin distribution. However, discontinuing the antibiotic after 4 years led to an increased rate of infection in the pediatric population, according to trial results published in PLoS Medicine.
“WHO recommends annual mass azithromycin administration in communities with at least 10% prevalence of trachomatous inflammation-follicular, or TF, in children, with further treatment depending on reassessment after 3 to 5 years,” Jeremy D. Keenan, MD, a professor at the University of California, San Francisco’s Proctor Foundation and an ophthalmologist with UCSF Health, and colleagues wrote. “However, the effect of stopping mass azithromycin distribution after multiple rounds of treatment is not well understood.”
To better understand how mass distribution of azithromycin affects the rate of ocular chlamydia in children, Keenan and colleagues conducted a cluster-randomized study in northern Ethiopia called the TANA I trial. Forty-eight communities received azithromycin annually or twice a year for 4 years. Then, communities were randomly assigned to either continue or discontinue treatment.
Three years after baseline, the researchers measured the prevalence of ocular chlamydial infection among children aged between 0 and 9 years.
Keenan and colleagues said the average antibiotic coverage was greater than 90% at all times in the group that was instructed to continue azithromycin treatment. When infection rates among children in the discontinuation group were examined, the researchers saw an increase from 8.3% at baseline (95% CI, 4.2%-12.4%) to 14.7% at 36 months (95% CI, 8.7%-20.8%). The rate of ocular chlamydia decreased among children who continued taking antibiotics — from 7.2% (95% CI, 3.3%-11%) at baseline to 6.6% (95% CI, 1.1%-12%) at 36 months.
“Communities in which annual or biannual mass distributions were continued for an additional 3 years experienced stabilization of infection and clinical disease, suggesting that antibiotics alone may not be enough to completely eliminate infection in severely affected areas,” Keenan and colleagues wrote. “However, continuing mass azithromycin distribution after 3 to 5 years is significantly better for maintaining low levels of ocular chlamydia than is discontinuing treatment.” – by Katherine Bortz
Disclosures: The authors report no relevant financial disclosures.