Integrated serosurveillance to assess disease elimination in coastal Ecuador: onchocerciasis, yaws, and trachoma

Antibodies measured in blood provide a sensitive measure of past infection. At the population-level, antibody responses are widely used to monitor pathogen elimination. Antibodies measured in blood samples from children along an urban-rural gradient in Ecuador showed no evidence of exposure to the pathogens that cause onchocerciasis or yaws, confirming their continued elimination in the region. However, antibody responses to chlamydia were common among children in rural villages during their first two years, motivating additional surveillance to assess trachoma endemicity in the area as its endemicity status is currently unknown. Trachoma is caused by ocular chlamydia infection, and these results indicate a need for additional surveillance to assess ocular infections and clinical signs of trachoma in this population.