CHLAMYDIA TRACHOMATIS

Chlamydias are gram-negative bacteria, with an obligatory intracellular energetic parasitism. Chlamydia trachomatis is divided in 15 serovars: Ab, B, Ba, or C that cause trachoma, D-K that cause pelvic inflammatory disease, urethritis, ectopic pregnancy, neonatal conjunctivitis and neonatal pneumonia, and L1, L2 and L3 responsible for lymphogranuloma venereum (LGV). Chlamydia trachomatis infections usually evolve in an asymptomatic way but may lead to tubal occlusion with a higher risk of extrauterine pregnancy and infertility. In women it mainly occurs before the age of 25 years, while in men it can still be diagnosed till the age of 35 years.

In Western Europe the prevalence of Chlamydia trachomatis infection has been estimated, according to WHO data, as between 2.7% (Italy) and 8.0% (Iceland).

A non-diagnosed and non-treated Chlamydia trachomatis infection can result in major epidemiological and socio-economic public health problems.

Most of the serological diagnostic assays for Chlamydia use purified elementary bodies but often the presence of lipopolysaccharide (LPS) can be cause of cross reactions between the three different species (pneumoniae, trachomatis and psittaci). This test uses purified elementary bodies specifically treated to exclude LPS cross reactivity and to allow a more specific determination of anti-Chlamydia trachomatis IgA and IgG antibodies.

Immunoenzymatic method for the qualitative determination of IgA and IgG-class antibodies to Chalmydia trachomatis in human serum, using a disposable device applied on the Chorus and Chorus TRIO instruments.The test is based on the ELISA principle (Enzyme Linked ImmunoSorbent Assay) which uses the reaction between the antibodies present in the tested sample and the immobilized antigen bound to solid phases.The immunoglobulins bind to the antigen through incubation with diluted human serum.The disposable devices contain all the reagents to perform the test when applied on the Chorus instruments. The results are expressed in Index (OD sample/OD cut-off).