SEROEPIDEMIOLOGY OF CHLAMYDIAL INFECTION AMONG A SEXUALLY-ACTIVE POPULATION IN BARBADOS

During a two-year period, sera from 1179 patients with urogenital trac t symptoms and from 256 controls were tested for IgG and IgA antibodie s to Chlamydia trachomatis, using a commercially prepared indirect imm unoperoxidase assay. Of the patient sera, 1051 (89%) were from female patients and 128 (11%) were from males. Specimens were received from p atients attending private practitioners (424), government polyclinics (348), the Queen Elizabeth Hospital (206), the Barbados Family Plannin g Association (117) and various other sources (84). Nine hundred and f ifty-nine of specimens (81%) from all patients had IgG titres of 64 or greater, and 441 (37%) had IgA titres of 16 or greater. A lower propo rtion of male patients (43%) than female patients (61%) had IgG titres of 128 or greater. Among 76 control females attending the antenatal c linic, IgG was detected in 76% and IgA in 16%, while among 75 adult bl ood donors, IgG was detected in 70% and IgA in 39%. A group comprising 97 asymptomatic children aged 9 months to 13 years, and 8 adolescents aged 14 - 18 years was also studied. IgG antibodies (titre greater-th an-or-equal-to 64) were detected in 13.4% of children and in 50% of th e adolescents. IgA antibodies were detected in only 1% of children and adolescents. Antibodies were not detected in children under the age o f 5 years. The detection of antibodies by indirect immunoperoxidase as say in such a high proportion of the population suggests that this met hod is of little value for diagnosis of infection with Chlamydia trach omatis.