Chlamydia << kluh MIHD ee uh >> is the common name for a group of bacteria that cause disease in animals and human beings. In the United States, genital chlamydia infection is the most common bacterial sexually transmitted disease (STD). It is caused by the bacterium Chlamydia trachomatis, which also causes another STD called lymphogranuloma venereum. Chlamydia strikes more than 1 million Americans each year, mostly young people under 25 years of age.
In men, symptoms of chlamydia appear about 7 to 21 days after infection. Most infected men develop a white or colorless discharge from the penis, accompanied by painful urination. The symptoms may go unnoticed, and they usually disappear after several months. Left untreated, the patient may infect other people.
In women, chlamydia can cause a vaginal discharge or pelvic pain, but many have no symptoms. The consequences of untreated infection in women can be especially severe. Infection can spread through the uterus and into the fallopian tubes, causing pelvic inflammatory disease (PID), a condition that may result in sterility, and rarely, death. Pregnant women who have chlamydia can transmit it to their babies during delivery. The germ may infect the baby’s lungs, causing pneumonia, and the eyes, causing conjunctivitis.
In some less developed countries, certain varieties of C. trachomatis can infect the eyes, especially in children. These germs are spread by nonsexual contact and perhaps by flies. People infected in this way may develop trachoma, which can lead to blindness.
Chlamydial infection can be diagnosed by laboratory tests done on a swab of genital fluids or a urine sample. Doctors often assume a patient has chlamydia if symptoms are present and gonorrhea infection cannot be confirmed. Doctors treat chlamydia with antibiotics. Treatment is most effective when given early in the disease. Strategies for avoiding the infection include using condoms during intimate sexual contact.
Other species of chlamydia cause disease in human beings. Chlamydophila pneumoniae is a common cause of respiratory infections. Scientists think it may also have a role in the development of heart disease. Chlamydia psittaci is usually transmitted from birds to people and can cause pneumonia or fever.
See also Gonorrhea; Sexually transmitted disease.
