Sexually Transmitted Diseases (STDs)

Chlamydia trachomatis Chlamydia is the most common sexually transmitted infection in humans and it is caused by the bacterium Chlamydia trachomatis . It affects 5% to 10% of the world’s population and it is particularly common in young adults under 25 years. It is a major public health concern due to its prevalence and potential long-term consequences. Antigen and Antibody Detection Assays

An estimated 100 million Chlamydia trachomatis infections occur annually among sexually active adolescents and young adults in the world. Its prevalence is due to the majority of cases (75% of women and 50% of men) having minimal to no symptoms, therefore it often goes undiagnosed and can be spread unknowingly. Infection is associated with non-gonococcal urethritis in men and several inflammatory reproductive tract syndromes in women such as inflammation of the uterine cervix and pelvic inflammatory disease (PID). If left untreated in women, 20% will become infertile, 18% will experience debilitating, chronic pelvic pain, and 9% will have a life- threatening tubal pregnancy. Furthermore, C. trachomatis infection during pregnancy leads to infant conjunctivitis and pneumonia and maternal postpartum endometriosis. In most cases, chlamydia can be easily treated with antibiotics with a cure rate of 95%. However, many people don’t know they have the disease until it has caused serious complications. Young adults under age 25 and others at high risk (e.g. pregnant women) should be tested for chlamydia once a year even if they are symptom-free.

CHLAMYDIA TRACHOMATIS MORPHOLOGY

Source: Nature.com

Diagnosis

Culture testing for C. trachomatis has been the reference standard, however antigen detection using ELISA-based assays, direct fluorescent antibody (DFA) tests and nucleic acid hybridization tests have increased in popularity due to their relative ease-of-use. EIA methods initially developed for the detection of

C. trachomatis measured lipopolysaccharide (LPS) antigen expressed by the chlamydial elementary bodies which is common to all four chlamydia species ( C. trachomatis, C. pneumoniae, C. psittaci , and C. pecorum ). Newer tests for C. trachomatis use antibodies against chlamydial heat shock protein 60 (cHSP60) or the major outer membrane protein (MOMP) which do not cross-react with the other chlamydia species or with other organisms that contain LPS.