Résumé
The Chlamydiae are obligate, intracellular bacteria. They are pathogens specific, causing a broad spectrum of infectious diseases. The micro-immunofluorescence test performed against Chlamydial organisms, using the antigens of the three species of Chlamydia [Chlamydia trachomatis, Chlamydia psittaci and Chlamydia pneumoniae], is the reference method to serological diagnosis of chlamydial infections. A sero-prevalency study in Sfax, performed in the laboratory of microbiology-immunology in the university hospital of Sfax, has shown the widespread of anti-Chlamydia antibodies in our region 45.2%: 4.7% antibodies to Chlamydia trachomatis, 0.5% antibodies to Chlamydia psittaci and 40% antibodies to Chlamydia pneumoniae. The applicability of the microimmunofluorescence technique has allowed to detect species-specific antibody and to permit a condiserable economy of regents and biological materials. However, the cross-reactions observed in 5.9% of cases and the difficulty to distinguish between a recent acute infection and past infection for lack of IgM antibody, make the diagnosis of chlamidial infectious by this method hard and hazardous