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Chlamydial and Other Infections
(See also Overview of Sexually Transmitted Diseases.)
Chlamydial infections include sexually transmitted diseases of the urethra, cervix, and rectum that are caused by the bacteria Chlamydia trachomatis. These bacteria can also infect the membranes that cover the whites of the eyes (conjunctiva) and the throat. Other bacteria, such as Ureaplasma and Mycoplasma, can also cause infections of the urethra.
Symptoms include a discharge from the penis or vagina and painful or more frequent urination.
If unnoticed or untreated in women, these infections can result in infertility, miscarriage, and an increased risk of a mislocated pregnancy.
DNA tests of a sample of the discharge or of urine can detect chlamydial infection.
Antibiotics can cure the infection, and sex partners should be treated at the same time.
Several bacteria can cause diseases that resemble gonorrhea. These bacteria include Chlamydia trachomatis (chlamydiae), Ureaplasma, and Mycoplasma. Laboratories can identify chlamydiae but have difficulty identifying the other bacteria.
Chlamydial infection is the most commonly reported sexually transmitted disease (STD). In the United States, over 1.4 million cases were reported in 2014. Because the infection frequently causes no symptoms, twice as many people may be infected.
In men, chlamydiae cause about half of the urethral infections (urethritis) not caused by gonorrhea. Most of the remaining urethral infections in men are probably caused by Ureaplasma urealyticum or Mycoplasma genitalium. In women, chlamydiae account for virtually all of the cervical infections (cervicitis) that produce pus and that are not caused by gonorrhea. Sometimes both sexes have gonorrhea and chlamydial infection at the same time.
Chlamydial infection can also be spread during oral sex, causing infection of the throat.
In men, symptoms of chlamydial urethritis start 7 to 28 days after the infection is acquired during intercourse. Typically, men feel a mild burning sensation in their urethra during urination and may have a clear or cloudy discharge from the penis. The discharge is usually less thick than the discharge in gonorrhea. The discharge may be small, and symptoms mild. However, early in the morning, the opening of the penis is often red and stuck together with dried secretions. Occasionally, the infection begins more dramatically—with a frequent urge to urinate, painful urination, and a discharge of pus from the urethra.
Many women with chlamydial cervicitis have few or no symptoms. But some have frequent urges to urinate, painful urination, and secretions of yellow mucus and pus from the vagina. Sexual intercourse may be painful.
Chlamydial throat infection usually causes no symptoms.
If the rectum is infected, people may have rectal pain or tenderness and a yellow discharge of pus and mucus from the rectum.
Without treatment, symptoms lessen within 4 weeks in about two thirds of people. However, chlamydial infections can have serious long-term consequences for women, even when their symptoms are mild or absent. Thus, detecting the infection in women and treating them is important, even if symptoms are absent.
In women, the infection may spread up the reproductive tract and may infect the tubes that connect the ovaries to the uterus (fallopian tubes). This infection, called salpingitis, causes severe lower abdominal pain. In some women, the infection spreads to the lining of the pelvis and abdominal cavity (peritoneum), causing peritonitis. Peritonitis causes more severe pain in the lower abdomen. These infections are considered pelvic inflammatory disease.
Sometimes infection concentrates in the area around the liver, in the upper right part of the abdomen, causing pain, fever, and vomiting—called the Fitz-Hugh-Curtis syndrome.
Complications include chronic abdominal pain and scarring of the fallopian tubes. The scarring can cause infertility and mislocated (ectopic) pregnancies.
In men, chlamydial infections may cause infection of the epididymis (epididymitis). The epididymis is the coiled tube on top of each testis (see Figure: Male Reproductive Organs). This infection causes painful swelling of the scrotum on one or both sides.
In either sex, chlamydiae may be transferred to the eye, causing infection of the clear membrane that covers the white of the eye (conjunctivitis).
Chlamydial genital infections occasionally cause a joint inflammation called reactive arthritis (previously called Reiter syndrome). Reactive arthritis typically affects only one or a few joints at once. The knees and other leg joints are affected most often. The inflammation seems to be an immune reaction to the genital infection rather than spread of the infection to the joints. Symptoms typically begin 1 to 3 weeks after the initial chlamydial infection. Reactive arthritis sometimes causes other problems, such as changes in the skin of the feet, problems with the eyes, and inflammation of the urethra.
Newborns may be infected with Chlamydia during delivery if their mother has a chlamydial cervical infection. In newborns, the infection may result in pneumonia or conjunctivitis (neonatal conjunctivitis).
Doctors suspect these infections based on symptoms, such as a discharge from the penis or cervix. In most cases, doctors diagnose chlamydial infections by doing tests that detect the bacteria’s unique genetic material (DNA). Usually, a sample of the discharge from the penis or cervix is used. For some types of these tests, a urine sample can be used. Thus, people can avoid the discomfort of having a swab inserted into the penis or having a pelvic examination to obtain a sample.
If doctors suspect infection of the throat or rectum, samples from those sites may be tested.
Gonorrhea, which is often also present, can be diagnosed using the same sample. Blood tests to check for human immunodeficiency virus (HIV) infection and syphilis are usually also done.
Specific tests for genital infections with Ureaplasma and Mycoplasma are not usually done, although new diagnostic tests are becoming available for mycoplasma. These infections are sometimes diagnosed in people with characteristic symptoms after gonorrhea and chlamydial infections are ruled out.
Because chlamydial infection is so common and because many infected women have no symptoms, tests to screen for chlamydial infection and other STDs are recommended for certain sexually active women and men.
Women who are not pregnant are screened if they have characteristics that increase their risk of infection:
The following pregnant women are screened at their first prenatal visit and again during the 3rd trimester:
If pregnant women have a chlamydial infection, they are treated, and tests are repeated 3 to 4 weeks after treatment to determine whether the infection was eliminated. These women are tested again within 3 months.
Heterosexual men can be screened if their risk of chlamydial infection is increased—for example, when they have several sex partners, when they are patients at an adolescent or STD clinic, or when they are admitted into a correctional facility.
Men who have sex with men are screened as follows:
These men are screened whether they use condoms or not. Tests are done using samples taken from the rectum or urethra.
The following general measures can help prevent chlamydial infections (and other STDs):
Regular and correct use of condoms (see How to Use a Condom)
Avoidance of unsafe sex practices, such as frequently changing sex partners or having sexual intercourse with prostitutes or with partners who have other sex partners
Prompt diagnosis and treatment of the infection (to prevent spread to other people)
Identification of the sexual contacts of infected people, followed by counseling or treatment of these contacts
Not having sex (anal, vaginal, or oral) is the most reliable way to prevent STDs but is often unrealistic.
Chlamydial, ureaplasmal, and mycoplasmal infections are treated with one of the following antibiotics:
Pregnant women are treated with azithromycin.
If gonorrhea is possible, an antibiotic such as ceftriaxone, injected into a muscle, is given at the same time to treat gonorrhea. Such treatment is needed because the symptoms of the two infections are similar and because many people have both infections at the same time.
If symptoms persist or return, they may be caused by other infections that are also present, or people may have become infected again. Tests for chlamydial infection and gonorrhea are repeated, and sometimes tests for other infections are done. Then people are treated with azithromycin or, if azithromycin was used before and was ineffective, with moxifloxacin.
Sex partners should be treated simultaneously if possible. Infected people and their sex partners should abstain from sexual intercourse until they have been treated for at least 1 week.
The risk of another chlamydial infection or another STD within 3 to 4 months is high enough that people should be tested again at that time.
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