Impact of Two Alternative Dosing Strategies for Trachoma Control in Niger

Trachoma is a disease of poverty, which in the hyperendemic areas affects all individuals by the time they are two years old. Active disease is concentrated in children and occurs sporadically in adults. Infection is more widespread. It is anticipated that 25% of the children will be blinded by this disease if they live to be 60 years of age. The blindness rates are higher in women, presumably because of their closer contact with children who can infect them and add to damage from infections the women had while young. This proposal is to better define how azithromycin in community-based treatment can be used to eliminate blinding trachoma. We will also take the opportunity to join these field studies with genetic epidemiologic studies to better understand the dynamic epidemiology of Chlamydia trachomatis infection in a trachoma endemic area. The empiric data generated from the treatment/follow-up studies, together with the information on sources and spread patterns from genetic epidemiology will be used to generate more robust models to guide future treatment/re-treatment protocols. We propose to conduct a randomized, community based trial in the Maradi region of Niger to test the hypothesis that two community wide azithromycin treatments, spaced one month apart, are significantly more effective in reducing ocular C. trachomatis infection and trachoma at one year compared to a single mass azithromycin treatment.