Chlamydia

Chlamydia is a common sexually transmitted infection caused by the bacterium Chlamydia trachomatis. Chlamydia is the most common STI in the United Kingdom and the United States, and is one of the most common in the world. It is estimated that around 1 million people in the United States are infected with chlamydia.

Chlamydia can be transmitted during vaginal, anal or oral sex, and can also be passed onto babies during vaginal birth. Between 50% and 75% of all women infected with cervical chlamydia - cervicitis - do not suffer any symptoms and are not aware they are infected. In men chlamydia is usually represented by a white discharge from the penis, with or without pain during urination. If left untreated chlamydia can lead to a number of other more severe health problems.



The World Health Organisation believes that chlamydia is a common cause of blindness worldwide, but also believes cases of blindness due to chlamydia are falling. In 1995 they estimated that as many as 15% of all cases of blindness were caused by chlamydia, with that figure falling to just 3.6% by 2002.

Signs and Symptoms

Chlamydia is known as the "Silent Epidemic" due to the large number of women that do not show symptoms of the infection. Around 50-75% of all cases of cervical chlamydia are asymptomatic, showing no symptoms, and can be present for months or years before detection. If symptoms do show they can include vaginal discharges and bleeding, pain in the abdomen, pain during sexual intercourse, fever, pain during urination, or the urge to urinate more frequently than usual. It can be passed on through vaginal, anal or oral sex. Around half of all women with asymptomatic chlamydia will go on to develop infections of the uterus, fallopian tubes, and/or ovaries. If left untreated, these infections can cause scarring inside the reproductive organs, which can lead to serious complications, such as chronic pelvic pain, problems becoming pregnant, and ectopic pregnancy.

In men, chlamydia shows symptoms in around 50% of cases. These symptoms can include pain whilst urinating, unusual discharge from the penis, swollen or tender testicles, and/or fever. The discharge - or purulent exudate - is generally less viscous and lighter than for gonorrhea. If left untreated it can spread to the testicles, causing epididymitis. Epididymitis can in rare cases cause sterility if not treated within 6-8 weeks.

Previously chlamydia conjunctivitis was the most important cause of blindness worldwide, however its role has diminished from 15% of cases in 1995 to 3.6% in 2002. The infection can be spread through sharing towels or cloths, coughing and sneezing, as well as hand-to-eye contact. Newborn babies can also develop chlamydia eye infection through contact with the infection during vaginal birth. Around half of all babies born to mothers with chlamydia will be infected with the disease, and in some cases it can cause spontaneous abortion, premature birth and conjunctivitis, which may lead to blindness and pneumonia.

Chlamydia can also cause rheumatlogical conditions in the form of reiter's syndrome, a combination of arthritis, conjunctivitis and urethritis. Around 15,000 men in the US develop the syndrome every year, and about 5,000 of those are affected by it permanently. It affects both sexes, but is more common in men.

Diagnosis and Treatment

Chlamydia is diagnosed using a nucleic acid amplification test (NAAT), which is performed on swab tests taken from the cervix in women and the urethra in men. This facilitates the performance of screening tests in settings where genital examination is impractical.

Chlamydia can be effectively cured using antibiotics once it is identified. Currently antibiotics such as azithromycin, doxycicline, erythromycin, or ofloxacin are recommended, with amoxicillin being recommneded for pregnant women.