Chlamydial Infections

Chlamydial Infections 2420
Photo by: Sebastian Kaulitzki

Chlamydial (kla-MID-ee-al) infections are caused by three species of microorganisms. Chlamydia trachomatis can cause eye or lung infections and can also infect the urinary and genital areas of both men and women. Chlamydia pneumoniae causes infections of the respiratory tract, and Chlamydia psittaci causes an illness, known as parrot fever, that is similar to the flu.


for searching the Internet and other reference sources



What Are the Diseases Caused by Chlamydial

Chlamydia trachomatis

In the United States, Chlamydia trachomatis (tra-KO-ma-tis) is responsible for more cases of sexually transmitted diseases (STDs) than any other organism. Sexually transmitted diseases are passed from one partner to another during sexual activity. It is estimated that between 4 and 8 million people are infected in the United States by Chlamydia trachomatis every year.

Chlamydia trachomatis also causes an eye infection called trachoma (tra-KO-ma), which is an inflammation of the membrane covering the eye. It causes the eye to become irritated and red with a thick discharge. Infants whose mothers' have Chlamydia infections may become infected during birth. These infants can develop eye infections a few days after birth or pneumonia several weeks after birth.

Chlamydia pneumoniae

Chlamydia pneumoniae (noo-MO-nee-eye) can cause infections in the respiratory tract. The result can be bronchitis, pneumonia, or pharyngitis * . In the United States it is one of the leading causes of pneumonia in people between the ages of 5 and 35.

Chlamydia psittaci

The illness psittacosis (sit-a-KO-sis) or parrot fever, is caused by Chlamydia psittaci carried by birds (mainly parrots, parakeets, and lovebirds). In human beings it causes an illness that is like the flu. Only people who work closely with birds, such as pet-store workers or those who train carrier pigeons, are liable to contract this disease.

How Are Chlamydial Infections Transmitted?

Chlamydial infections are passed from one person to another through direct contact. Sexually transmitted chlamydia is passed from one person to another by direct sexual contact, and the people at most risk are those who have unprotected sex or multiple sex partners.

Parrot fever is caused by inhalation of dust from feathers and droppings or by the bite of an infected bird. Trachoma is transmitted by eye-to-eye or hand-to-eye contact, eye-seeking flies, or by sharing contaminated articles such as towels, handkerchiefs, or eye makeup.

Who Is at Risk for Chlamydial Infections?

Those most at risk for Chlamydia trachomatis infections are people who are sexually active with someone who is infected. Unborn babies of mothers with the disease are also at risk of infection during birth. People who work with birds that are illegally brought into the United States are at risk of infection with Chlamydia psittaci.

* pharyngitis (far-in-JI-tis) is inflammation of the pharynx, part of the throat.

What Are the Symptoms of Chlamydial Infections?

The most common symptom of chlamydia trachomatis infections in men or women is a burning sensation during urination. Unfortunately, many women who are infected do not have any symptoms. If they are pregnant and do not know that they have been infected, they may unknowingly pass the disease on to their baby at birth. Besides a burning sensation when urinating, a person with chlamydia trachomatis may have an abnormal discharge from the genital area. The genital area may become inflamed, and in women the inflammation can spread to the internal reproductive organs. Women then may develop a disease called pelvic inflammatory disease (PID). This can cause a woman to become infertile, that is, unable to become pregnant and have children.

Trachoma is still found in poor areas of the southeast United States and in poor areas of other countries around the world. Trachoma infection causes eyelid swelling, tearing, and sensitivity to light. Seven to ten days after the symptoms start, small lumps develop inside the eyelid and gradually increase in size and number. If not treated, scarring of the cornea * occurs, and vision is diminished or completely lost.

Parrot fever has an incubation period of one to three weeks. There is then a sudden onset of fever, chills, loss of appetite, and fatigue. Later a cough develops that progresses to pneumonia. Up to 30 percent of people who have untreated parrot fever die.

How Are Chlamydial Infections Treated?

Chlamydial infections can be successfully treated with antibiotics. Because untreated chlamydial infections can lead to serious and permanent problems, possible infections should be treated and evaluated by a doctor as soon as possible. If a person is being treated for genital infections due to chlamydia, his or her partner should also be tested and treated. Parents of newborn children should be alert to the condition of the baby's eyes. If they become red, swollen, or have a thick discharge, a physician should be contacted immediately. Persistent coughing by a newborn is also a signal to call a doctor.

Can Chlamydial Infections Be Prevented?

The best prevention for genital infection by chlamydia is to avoid sexual contact with an infected person. Abstaining from sexual relations is the only certain way to avoid contracting Chlamydia trachomatis since it is common for infected people not to know they have the infection.

Parrot fever can be prevented by buying birds from reputable pet stores or breeders who sell imported birds that have been quarantined * , examined, and fed antibiotic-treated bird feed for 45 days.

* cornea (KOR-ne-a) is the transparent structure covering the front chamber of the eye,

* quarantine is the enforced isolation (for a fixed period) of apparently well persons or animals who may have been exposed to infectious disease.



Stoffman, Phyllis. Family Guide to Preventing and Treating 100 Infectious Illnesses. New York: John Wiley & Sons, 1995.

Thacker, John, and Rachel Kranz. Straight Talk about Sexually Transmitted Diseases. New York: Facts on File, 1993.

Organizations website has dozens of articles on many types of infections, including chlamydia.

American Social Health Association (ASHA), P.O. Box 13827, Research Triangle Park, NC 27709.
Telephone 919-361-8400

See also
Pelvic Inflammatory Disease
Sexually Transmitted Diseases

User Contributions:

Comment about this article, ask questions, or add new information about this topic: