Méthodes de diagnostic des infections à Chlamydiae : directes et/ou sérodiagnostic ? Que choisir ?

Three species are responsible for Chlamydia infections in men: Chlamydia trachomatis, a main bacterial agent of sexually transmitted infection, Chlamydia pneumoniae, responsible for community respiratory tract infection and Chlamydia psittaci from avian origin, occasionally responsible for pneumonia. The diagnosis of C. trachomatis infection is mainly based on direct detection by nucleic acid amplification gene tests (NAAT) with commercialized tools, sensitive and specific. Serodiagnosis has an interest in evaluating the extent of disease. The diagnosis of C. pneumoniae infection has suffered from the lack of specificity of the techniques used after its discovery. It seems that the incidence of respiratory C. pneumoniae infection has been largely overestimated. In the present state of our knowledge, serological techniques could be abandoned in favor of direct techniques such as NAATs with commercial kits, sensitive and specific, in duplex with Mycoplasma pneumoniae. For C. psittaci, diagnosis should be restricted to expert laboratories, due to the lack of available commercial direct techniques and the need of expertise required for interpreting the serodiagnosis results.