A study of human respiratory tract chlamydial infections in Cambridgeshire 1986–88

Abstract

SUMMARYHuman respiratory tract chlamydial infections have been studied in Cambridge-shire for many years, but until recently we have been unable to distinguish between infection withChlamydia psittaciOrChlamydia pneumoniae(TWAR). In this study, we have employed the micro-immunofluorescence (micro-IF) test for this purpose and to look for the relative incidence ofC. psittaciandC. pneumoniaeinfections in Cambridgeshire. Among 50 patients with community-acquired respiratory tract symptoms whose serum samples had Chlamydia complement fixation test titres ≥ 64, 25 had evidence of recentC. psittaciorC. pneumoniaeinfection. Nineteen (76%) of the 25 patients had evidence of recentC. psittaciinfection and of these 16 (84%) had recently had contact with birds. Six patients (24%) had evidence of recentC. pneumoniaeinfection, and of these, only two (33% had recently had contact with birds). WhileC. psittaciwas grown from several of the birds associated with humanC. psittaciinfection, it was not cultured from any of the birds in contact with the two humanC. pnemoniaecases.