Persisting inapparent chlamydial infection in a trachoma endemic community in The Gambia.

In a Gambian village with endemic trachoma, C. trachomatis was isolated from some 50% of children with active trachoma but from only 1% of adults with scarring sequelae. One possibility is that individuals with progressive scarring disease have clinically inapparent, non-productive infection which cannot be detected by cell culture. In whole village survey, 12% of 808 people carried ocular chlamydial antigen detected by EIA. Around 70% of antigen positive children were clinically active. By contrast, for adults age greater than 25 years, only 10% of antigen positives were clinically active. Antigen positive adults were twice as likely to develop scarring disease and longitudinal studies suggest that they are intermittently infectious. Implications for the pathology and prevention of trachoma are discussed.