May 2002
Chlamydial Infection
What is Chlamydial Infection?
Chlamydial ("kla-MID-ee-uhl") infection is a curable sexually
transmitted infection (STI), which is caused by a bacterium called Chlamydia
trachomatis. You can get genital chlamydial infection during oral,
vaginal, or anal sexual contact with an infected partner. It can cause
serious problems in men and women as well as in newborn babies of infected
mothers.
Chlamydial infection is one of the most widespread bacterial STIs in
the United States. The U.S. Centers for Disease Control and Prevention
(CDC) estimates that more than 4 million people are infected each year.
Health economists estimate that chlamydial infections and the other
problems they cause cost Americans more than $2 billion a year.
What Are the Symptoms of This STI?
Because chlamydial infection does not make most people sick, you can have
it and not know it. Those who do have symptoms may have an abnormal discharge
(mucus or pus) from the vagina or penis or pain while urinating. These
early symptoms may be very mild. Symptoms usually appear within one to
three weeks after being infected. Because the symptoms may be mild or
not exist at all, you might not seek care and get treated.
The infection may move inside the body if it is not treated. There,
it can cause pelvic inflammatory disease (PID) in women and epidydimitis
in men, two very serious illnesses.
C. trachomatis can cause inflamed rectum and inflammation
of the lining of the eye ("pink eye"). The bacteria also can
infect the throat from oral sexual contact with an infected partner.
How Does the Doctor Diagnose Chlamydial Infection?
Chlamydial infection is easily confused with gonorrhea because the symptoms
of both diseases are similar and the diseases can occur together, though
rarely.
The most reliable ways to find out whether the infection is chlamydial
are through laboratory tests. Usually, a doctor or other health care
worker will send a sample of pus from the vagina or penis to a laboratory
that will look for the bacteria.
The urine test does not require a pelvic exam or swabbing of the penis.
Results from the urine test are available within 24 hours.
How is Chlamydial Infection Treated?
If you are infected with C. trachomatis, your doctor or other
health care worker will probably give you a prescription for an antibiotic
such as azithromycin (taken for one day only) or doxycycline (taken for
seven days) to treat people with chlamydial infection. Or, you might get
a prescription for another antibiotic such as erythromycin or ofloxacin.
Doctors may treat pregnant women with azithromycin or erythromycin,
or sometimes, with amoxicillin. Penicillin, which doctors often use
to treat some other STIs, won't cure chlamydial infections.
If you have chlamydial infection:
- Take all of the prescribed medicine, even after symptoms disappear.
- If the symptoms do not disappear within one to two weeks after finishing
the medicine, go to your doctor or clinic again.
- It is very important to tell your sex partners that you have chlamydial
infection so that they can be tested and treated.
What Can Happen if the Infection is Not Treated?
In women, untreated chlamydial infections can lead to PID. In men, untreated
chlamydial infections may lead to pain or swelling in the scrotal area,
which is a sign of inflammation of a part of the male reproductive system
located near the testicles known as the epididymis. Left untreated, these
complications can prevent people from having children.
Each year up to 1 million women in the United States develop PID, a
serious infection of the reproductive organs. As many as half of all
cases of PID may be due to chlamydial infection, and many of these don't
have symptoms. PID can cause scarring of the fallopian tubes, which
can block the tubes and prevent fertilization from taking place. Researchers
estimate that 100,000 women each year become infertile because of PID.
In other cases, scarring may interfere with the passage of the fertilized
egg to the uterus during pregnancy. When this happens, the egg may attach
itself to the fallopian tube. This is called ectopic or tubal pregnancy.
This very serious condition results in a miscarriage and can cause death
of the mother.
Can Chlamydial Infection Affect a Newborn Baby?
A baby who is exposed to C. trachomatis in the birth canal during
delivery may develop an eye infection or pneumonia. Symptoms of conjunctivitis
or "pink eye," which include discharge and swollen eyelids,
usually develop within the first 10 days of life.
Symptoms of pneumonia, including a cough that gets steadily worse and
congestion, most often develop within three to six weeks of birth. Doctors
can treat both conditions successfully with antibiotics. Because of
these risks to the newborn, many doctors recommend that all pregnant
women get tested for chlamydial infection.
How Can I Prevent Getting Chlamydial Infection?
You can reduce your chances of getting chlamydia or of giving it to your
partner by using male latex condoms correctly every time you have sexual
intercourse.
If you are infected but have no symptoms, you may pass the bacteria
to your sex partners without knowing it. Therefore, any doctors recommend
that anyone who has more than one sex partner, especially women under
25 years of age, be tested for chlamydial infection regularly, even
if they don't have symptoms.
What Research is Going On?
Scientists are looking for better ways to diagnose, treat, and prevent
chlamydial infections. NIAID-supported scientists recently completed sequencing
the genome for C. trachomatis. The sequence represents an encyclopedia
of information about the organism. This accomplishment will give scientists
important information as they try to develop a safe and effective vaccine.
Developing topical microbicides (preparations that can be inserted into
the vagina to prevent infection) that are effective and easy for women
to use is also a major research focus.
For More Information About Chlamydial Infection Contact:
National Institute of Allergy and Infectious Diseases
National Institutes of Health
31 Center Drive, MSC 2520
Bethesda, MD 20892-2520 http://www.niaid.nih.gov
National Library of Medicine
MEDLINEplus
8600 Rockville Pike
Bethesda, MD 20894
1-800-338-7657
http://medlineplus.gov
Centers for Disease Control and Prevention
1600 Clifton Road
Atlanta, GA 30333
1-888-232-3228
http://www.cdc.gov
National STD and AIDS Hotline
1-800-227-8922 or 1-800-342-2437 (24 hours a day, 7 days a week)
American Social Health Association
P.O. Box 13827
Research Triangle Park, NC 27709-9940
http://www.ashastd.org
NIAID is a component of the National Institutes of Health
(NIH), which is an agency of the Department of Health and Human Services.
NIAID supports basic and applied research to prevent, diagnose, and
treat infectious and immune-mediated illnesses, including HIV/AIDS
and other sexually transmitted diseases, illness from potential agents
of bioterrorism, tuberculosis, malaria, autoimmune disorders, asthma
and allergies.
News releases, fact sheets and other NIAID-related
materials are available on the NIAID Web site at http://www.niaid.nih.gov.
Prepared by:
Office of Communications and Public Liaison
National Institute of Allergy and Infectious Diseases
National Institutes of Health
Bethesda, MD 20892
Last Updated November 21, 2003 (alt)
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