Chlamydia is currently one of the most common sexually transmitted diseases — about 4 million cases of chlamydia occur in the USA each year. However, about half of all men and three-quarters of all women who have chlamydia have no symptoms and don't know that they have the disease. The disease is transmitted by the Chlamydia trachomatis bacterium. It can be serious but it is easily cured if detected in time. It is also, and possibly more importantly, the biggest preventable cause of blindness in the world. Blindness occurs as a complication of trachoma (chlamydia conjunctivitis). Contents 1 Features 2 Treatment 3 Prevention 4 Pathophysiology 5 Diseases caused by chlamydia 6 Chlamydia in nonhumans 7 External links Features Almost half of all women who get chlamydia and aren't treated by a doctor will get pelvic inflammatory disease (PID), a generic term for infection of the uterus, fallopian tubes, and/or ovaries. PID can cause scarring inside the reproductive organs, which can later cause serious complications, including chronic pelvic pain, difficulty becoming pregnant, ectopic (tubal) pregnancy, and other dangerous complications of pregnancy. Chlamydia causes 250,000 to 500,000 cases of PID every year in the U.S. [1] In women, chlamydia may not cause any symptoms, but symptoms that may occur include: unusual vaginal bleeding or discharge, pain in the abdomen, painful sexual intercourse, fever, painful urination or the urge to urinate more frequently than usual. In men, chlamydia may not cause any symptoms, but symptoms that may occur include: a painful or burning sensation when urinating, an unusual discharge from the penis, swollen or tender testicles, or fever. Chlamydia in men can spread to the testicles, causing epididymitis, which can cause sterility. Chlamydia causes more than 250,000 cases of epididymitis in the USA each year. Chlamydia may also cause Reiter's Syndrome, especially in young men. About 15,000 men get Reiter's Syndrome from chlamydia each year in the USA, and about 5,000 are permanently affected by it. As many as half of all infants born to mothers with chlamydia will be born with the disease. Chlamydia can affect infants by causing spontaneous abortion (miscarriage), premature birth, blindness, and pneumonia. Treatment Fortunately, chlamydia can be effectively cured with antibiotics once it is detected. Current Centers for Disease Control guidelines provide for the following treatments: Azithromycin 1 gram by mouth once, or Doxycycline 100 milligrams twice daily for seven days. Prevention Because chlamydia is so common and because it often doesn't produce symptoms, it is especially important to take precautions against sexually transmitted disease by practicing safer sex. Pathophysiology Chlamydiae replicate intracellularly, within a membrane-bound structure termed an inclusion. It is inside this inclusion, which somehow avoids lysosomal fusion and subsequent degradation, that the metabolically inactive "elementary body" (EB) form of Chlamydia becomes the replicative "reticulate body" (RB). The multiplying RBs then become EBs again and burst out of the host cell to continue the infection cycle. Since Chlamydiae are obligate intracellular parasites, they cannot be cultured outside of host cells, leading to many difficulties in research. Diseases caused by chlamydia Chlamydia trachomatis can cause genital infections, conjunctivitis, pelvic inflammatory disease, pneumonia, urethritis, Fitz-Hugh-Curtis syndrome, Reiter's syndrome and lymphogranuloma venereum Chlamydia in nonhumans An outbreak of the human-borne sexually-transmitted disease was discovered in penguins at the San Francisco Zoo in May, 2005. Officials said that the disease was probably first contracted in February of that year, and was not sexually-transmitted. One theory links the outbreak to seagull droppings, but the actual cause remains unknown. Twelve penguins died from the disease, while fifty-five survived. See Chlamydia strikes penguin colony for more information. Chlamydia has also become a problem in Koala populations. External links Sexually Transmitted Diseases/Infections Resource Center from the Association of Reproductive Health Professionals "Chlamydia: Questions and Answers" from Planned Parenthood" Chlamydia fact sheet from the Center for Disease Control eMedicine Health Chlamydia NetDoctor Chlamydia fact sheetda:Klamydia Search Term: "Chlamydia" Categories: Sexually-transmitted diseases