Targeted Antibiotics for Trachoma: A Cluster-Randomized Trial

Area of Science:

• Ophthalmology
• Infectious Diseases
• Public Health

Background:

• Current trachoma guidelines advocate for community-wide mass azithromycin administration.
• A targeted antibiotic strategy could potentially decrease the overall volume of antibiotics used.

Purpose of the Study:

• To evaluate the efficacy of a targeted azithromycin distribution strategy for reducing ocular chlamydia prevalence in Ethiopian communities.
• To compare the effectiveness of targeted treatment versus mass treatment and delayed treatment in controlling trachoma.

Main Methods:

• A randomized trial involving 48 Ethiopian communities with mass, targeted, or delayed azithromycin distribution.
• Targeted arm: Azithromycin administered to children aged 6 months to 5 years with ocular chlamydia evidence, thrice over one year.
• Primary outcome: Ocular chlamydia prevalence at 12 and 24 months, analyzed for superiority (targeted vs. delayed) and noninferiority (targeted vs. mass) in specific age groups.

Main Results:

• Ocular chlamydia prevalence averaged 16.7% in the targeted arm versus 22.3% in the delayed arm among 0-5 year-olds (months 12-24).
• Among 8-12 year-olds, the final prevalence was 13.5% in the targeted arm compared to 5.5% in the mass treatment arm.
• The targeted approach did not achieve noninferiority against mass treatment, with a higher adjusted risk difference (8.5 pp) in the targeted group.

Conclusions:

• Targeted antibiotic treatment for infected preschool children did not significantly reduce ocular chlamydia compared to untreated communities.
• The targeted strategy did not meet noninferiority criteria when compared to mass azithromycin distributions.
• In hyperendemic trachoma areas, targeted approaches may necessitate broader population treatment to be effective.