ELISA-VIDITEST anti-Chlamydia trachomatis IgM kit is intended for the qualitative detection of anti-Mycoplasma pneumoniae antibodies in human serum and human plasma. The laboratory diagnostic procedures in C. pneumoniae infections involve the direct pathogen detection (an isolation of the pathogen, direct antigen detection in cervical, vaginal and urethral swabs or nucleic acid amplification tests from urine – PCR, LCR) and serology tests that reveal specific IgG, IgA and IgM antibodies. Primary chlamydial infection is characterized by the predominant IgM response after 2 to 4 weeks from infection and the delayed IgG and IgA response after 6 to 8 weeks. After the acute C. trachomatis infection IgM antibodies usually decrease and become undetectable in 2 to 6 months. IgG antibody titres decrease slowly, whereas IgA antibodies tend to disappear rapidly When primary chlamydia infection is suspected, the detection of IgM is highly diagnostic. However, in recurrent or chronic infections the prevalence of IgM is low and therefore the absence of IgM does not necessarily exclude an on-going infection. In reinfections, IgG and IgA levels rise quickly. IgA antibodies have shown to be a reliable immunological marker of primary, chronic and recurrent infections. These antibodies usually decline rapidly to baseline levels following treatment and eradication of the chlamydia infection, however may persist for several months. The persistence of the elevated IgA antibody titres is generally considered as the sign of chronic infection.