DIAGNOSTIC UTILITY OF PCR-ENZYME IMMUNOASSAY, CULTURE, AND SEROLOGY FOR DETECTION OF CHLAMYDIA-PNEUMONIAE IN SYMPTOMATIC AND ASYMPTOMATIC PATIENTS

To assess the utility of PCR-enzyme immunoassay (EIA) for diagnosis of acute infection with Chlamydia pneumoniae, we compared tissue culture , PCR-EIA, direct fluorescent-antibody (DFA) stain, and serology in st udies with 56 patients with respiratory symptoms and 80 asymptomatic p ersons. Thirty-five patients were positive by either culture or PCR-EI A, and 101 were negative by both assays. Thirty specimens from symptom atic patients and one from an asymptomatic patient were culture positi ve; 23 of these were also PCR-EIA positive. Of the eight culture-posit ive, PCR-EIA-negative specimens, five were DFA negative and three were DFA positive. Four additional specimens were culture negative and PCR -EIA positive; of these, three were DFA positive and one was DFA negat ive. When we used culture- and/or DFA-positive results as a reference or ''gold standard,'' the sensitivity and specificity of PCR were 76.5 and 99.0%, respectively. When we used PCR and/or DFA-positive results as the reference, the sensitivity of culture was 87.5%. On the basis of single acute serum specimens, only 8 of these 35 patients had diagn ostic antibody titers. Of the asymptomatic patients, 75% had immunoglo bulin G or immunoglobulin M antibody to C. pneumoniae; 15 (18.8%) of t hese had antibody levels considered to be diagnostic of acute infectio n. This multicenter study indicates that culture and/or PCR-EIA is mor e reliable for prompt diagnosis of C. pneumoniae infection than single -point serology alone.