SEROEPIDEMIOLOGIC STUDY OF CHLAMYDIA-PNEUMONIAE AND OTHER CHLAMYDIAL SPECIES IN A HYPERENDEMIC AREA FOR TRACHOMA IN THE SUDAN

Sera of inhabitants of Angola village in central Sudan were investigat ed for the prevalence of antibodies to Chlamydia trachomatis, C. pneum oniae, and C. psittaci by the microimmunofluorescence (MIF) test. Clin ical examination of 616 persons showed that the village is hyperendemi c for trachoma. Of the 448 children examined, 334 (75%) had signs of a ctive trachoma. The corresponding prevalence in the 168 adults was 25% . Using MIF, antibodies to C. trachomatis were found in the sera of 27 (81%) children and of 37 (88%) adults with trachoma. Antibodies to C. pneumoniae occurred in 13% and 24% of the preschool and school tracho matous children, respectively, and in 64% of the adults, which reflect s earlier exposure to C. pneumonia in the Sudan than generally reporte d from temperate zones. Antibodies to C. psittaci were found in 6% of the children less than 16 years old and in 17% of the adults. Of the p atients with trachoma, 16% had antibodies to both C. trachomatis and C . pneumoniae. The prevalence of multiple antibodies to Chlamydia incre ased with age. Antibodies to all three species occurred in 3% of the p atients. The study does not support the existence of protective immuni ty between C. pneumoniae, C. trachomatis, and C. psittaci, as shown by the high prevalence of chlamydial antibodies in the hyperendemic trac homa community studied.