Chlamydia is one of the most common sexually transmitted infections. The infection is transmitted via unprotected vaginal, oral or anal sex with an infected person. It can also be transmitted from an infected mother to a baby during childbirth.
The infection is most commonly reported in sexually active women below 25 years of age. The bacteria Chlamydia trachomatis is carried in the semen or vaginal fluid of an infected person. Long-term Chlamydia infection can cause serious consequences in both males and females and may even lead to infertility.
Nearly 70 to 80% of females and almost 50% of males with the infection show no symptoms. Therefore, screening for the infection to detect, treat and prevent its spread to unsuspecting sexual partners is vitally important.
The U.S. Preventive Services Task Force (USPSTF) and the American Academy of Family Physicians both recommend screening for Chlamydia in women below 25 years of age. The American College of Obstetricians and Gynecologists recommends screening pregnant women who are at risk of having Chlamydia infection and the Centers for Disease Control and Prevention recommend universal screening for Chlamydia in pregnant women.
The types of specimens that can be screened for Chlamydia include:
- Urine sample
- Vaginal swab
- Cervical swab
- Rectal swab
- Pharyngeal or throat swab
Nowadays, the preferred tests are nucleic acid amplified tests (NAATs) which are recommended by the Centers for Disease Control and Prevention (CDC) for diagnosis of Chlamydia and gonorrhea. These tests can also detect non-living bacteria and may therefore detect the infection even if the bacteria have died in transit of the specimen. The four commercially available NAATs use urine, cervical or vaginal specimens.
Reviewed by Sally Robertson, BSc