POLYMERASE CHAIN-REACTION FOR THE DETECTION OF OCULAR CHLAMYDIAL INFECTION IN TRACHOMA-ENDEMIC COMMUNITIES

Polymerase chain reaction (PCR) with primers derived from the sequence of the cryptic chlamydial plasmid was evaluated for the detection of ocular chlamydial infection in trachoma-endemic populations and was us ed to explore further the relationship between ocular chlamydial infec tion and clinical signs of trachoma. It was more sensitive than other laboratory techniques, especially for mild cases of trachoma, in detec ting infection in 144 (72%) of 200 who fulfilled the World Health Orga nization case definition. Of 1132 subjects who did not fulfill these c riteria, 85 (7.5%) were PCR-positive, but about one-third of these 85 subjects had minor signs of trachoma. Clinically negative subjects who were PCR-positive were more likely than PCR-negative subjects to have acquired signs of disease at 1 and 6 months of follow-up. Clinical si gns were twice as likely to have resolved after 1 month in PCR-negativ e subjects with disease than in those who were PCR-positive.