Biannual antibiotic treatments may help eliminate trachoma in severely affected areas of Africa

Distributing antibiotics twice each year may help to at least locally eliminate the ocular chlamydial infection associated with trachoma among preschool-aged children in severely affected areas of Africa, according to a study published in Journal of the American Medical Association.

Muluken Melese, MD, MPh, and colleagues randomly assigned all residents of 16 villages located in the Gurage Zone of rural Ethiopia to receive either annual or biannual mass azithromycin administrations between March 2003 and April 2005. Overall, 14,897 of 16,403 eligible residents (90.8%) aged 1 year and older received their scheduled treatment; residents in eight villages received a single annual dose and those in the remaining eight villages received biannual doses, according to the study.

At 2 years, the prevalence of ocular chlamydial infections had reduced from a mean of 42.6% to 6.8% among the once-yearly-treated villages.

Among residents treated two times per year, the prevalence of the infection had reduced from 31.6% at baseline to 0.9% at 2 years, according to the study.

"Biannual treatment was associated with a lower prevalence at 24 months (P = .03, adjusting for baseline prevalence)," the authors said.

Also at 24 months, investigators found no signs of the infection in six villages treated biannually and in one village treated annually, according to the study.