Chlamydia is a highly common sexually transmitted infection (STI) caused by the bacterium Chlamydia trachomatis. This infection is frequently asymptomatic, allowing for its silent spread. Simple, dry skin-to-skin contact, such as hugging or general touching, does not transmit Chlamydia. The infection requires a specific transmission route involving infected secretions or mucous membranes.
Why Chlamydia Requires Mucous Membrane Contact
Chlamydia trachomatis is an obligate intracellular bacterium, meaning it must live inside the cells of a host to survive and replicate. This bacterium is adapted to infect the soft, moist linings of the body known as mucous membranes. The dry, protective surface of external skin is an inhospitable environment where the bacteria cannot penetrate or survive.
These specialized membranes are found in the urethra, cervix, rectum, throat, and the lining of the eye. They offer the specific cellular environment necessary for the bacteria to complete its life cycle. Transmission requires a direct route where infected secretions from one mucous membrane come into contact with another.
Defining the Actual Transmission Routes
Transmission of Chlamydia occurs primarily through the exchange of genital fluids or contact between infected mucous membranes during sexual activity. The most common activities leading to infection are unprotected vaginal or anal sex. Transmission can occur even without ejaculation, as contact with infected vaginal fluid or semen is sufficient.
Oral sex is a confirmed, though less common, route of transmission, as the bacteria can infect the throat. Touching genitals together without full penetration can also transmit the bacteria if infected secretions are exchanged. The bacteria can infect the eyes if infected genital fluid is transferred via the hand.
Mother-to-child transmission during delivery is a significant route. A baby passing through the birth canal of an infected mother can acquire the infection, potentially resulting in conjunctivitis or pneumonia in the newborn. Infection can also spread to the rectum from the vagina in adults, such as by accidental transfer or wiping.
Recognizing Signs and Seeking Testing
A majority of people infected with Chlamydia (approximately 70-80% of women and 50% of men) do not experience any symptoms. This lack of symptoms significantly contributes to the spread of the bacterium. When symptoms do appear, they usually manifest one to three weeks after exposure.
Common signs in women include an abnormal vaginal discharge, pain during urination, and bleeding between periods. In men, symptoms may involve a discharge from the penis, a burning sensation when urinating, or pain and swelling in the testicles. Since symptoms are often absent or mild, routine screening is recommended for sexually active individuals, especially those under age 25. Diagnosis is straightforward, typically involving a urine sample or a swab, and the infection is easily cured with antibiotics.