Purpose: To determine the risk of infection with Chlamydia trachomatis in children who are migrants to communities who are undergoing mass drug administration (MDA), and if their neighborhoods have higher rates of infection over time. Methods: In four communities in Kongwa, Tanzania, all children were enrolled in a longitudinal study of infection and trachoma. New children were identified at census updates as having not been in the community at the previous census. Within communities, neighborhoods were defined as spatially close groups of households, or "balozi". All children in the communities were invited to be examined for trachoma, and have ocular swabs taken for evidence of infection. Trachoma was graded using the World Health Organization simplified grading scheme, and swabs were processed using Amplicor. Results: Children who were migrants were more likely to be infected and to have trachoma than children who were resident in the community, which was significant by the time of the survey following the third year of MDA (odds ratio, OR, 2.49, 95% confidence interval, CI, 1.03-6.05). The neighborhoods where newcomers resided were more likely to have infection a year later than neighborhoods with no migrants, which was most pronounced following the third year of MDA (OR 2.86, 95% CI 1.07-7.65). Conclusion: Migrants to communities may be an important source of re-emergent infection, especially as MDA lowers infection among residents. Highly migrant populations may need a special surveillance and treatment program to avoid slowing progress in communities under MDA. © Informa Healthcare USA, Inc.

Population Trachoma Tanzania Prospective study Ocular Chlamydia trachomatis

prospective study household Community-Acquired Infections longitudinal study multicenter study tetracycline physiology trachoma clinical trial community program Follow-Up Studies follow up human Prospective Studies community risk assessment Odds Ratio eye ointment statistics and numerical data controlled study priority journal randomized controlled trial groups by age neighborhood drug administration Humans migrant azithromycin Adolescent Infant, Newborn male preschool child female Infant risk factor Risk Factors Child, Preschool newborn time to treatment prevalence Article mass drug administration infection control major clinical study adult migration infection risk Tanzania endemic disease Endemic Diseases world health organization single drug dose antiinfective agent Transients and Migrants Anti-Bacterial Agents Chlamydia trachomatis Child