Prevalence and risk factors for trachoma and ocular Chlamydia trachomatis infection in Niger

Aims: To determine the association of personal and household risk factors for trachoma and ocular Chlamydia trachomatis infection in Niger. Methods: 12 villages were randomly selected. A census of all households was carried out, and 651 children aged 1 - 5 years were randomly selected and examined. Household and personal characteristics were determined, trachoma was clinically assessed and a swab for ocular C trachomatis infection was taken. Results: The prevalence of trachoma was 43% (95% confidence interval (CI) 39% to 47%) and of infection was 21% (95% CI 18% to 24%). Children aged 3 - 5 years had a stronger association of clinical signs with infection, compared with those aged 1 - 2 years. Those with unclean faces were three times more likely to have clinical trachoma or ocular C trachomatis infection, compared with those with clean faces (OR 3.1 (95% CI 1.6 to 6.2) and 3.0 (95% CI 1.4 to 6.3), respectively). 75% of compounds were within 30 min of a water source. Flies on the face were a risk factor for trachoma but not for C trachomatis infection. Conclusions: The different association of clinical signs with infection in younger versus older children may be an age-dependent difference in the duration of clinical disease. In Niger, unclean faces are a major risk factor for trachoma. The ready availability of water for washing suggests that further research on the effect of a strong health education campaign promoting clean children is warranted in this area.