Diagnosis of Chlamydia trachomatis Infections by Direct Immunofluorescence Staining of Genital Secretions

Because few clinicians have access to laboratories offering cell culture confirmation of suspected Chlamydia trachomatis genital infections, we evaluated a diagnostic method in which fluorescein-conjugated monoclonal antibodies were used to directly identify C. trachomatis elementary bodies in slides made from genital secretions. Compared with culture results, the direct smear had a sensitivity of 9 2 % and a specificity of 96 % in 576 men, most of whom had symptoms and signs of urethritis. Among 595 women attending the same clinics, sensitivity of the direct smear for cervical infection was 8 9 % and specificity was 99%. In 225 pregnant women screened in a prenatal or abortion clinic, the sensitivity and specificity of the test were 86 % and 9 9 % respectively. Direct detection of elementary bodies in genital smears offers a