Chlamydia trachomatis infection and treatment

Chlamydia Trachomatis

Chlamydia is the most common and frequently occurring sexually transmitted disease in the United States. According to a recent CDC report there are more than 2.8 million persons infected every year. [CDC] The disease is caused by a bacterium known as Chlamydia trachomatis which is also found to exist as 15 different serotypes. The estimated annual treatment costs for Chlamydia is around $2 billion. The asymptotic nature of the disease presents a big problem in the early diagnosis and a substantial number of infected persons are unaware of their condition. Though totally curable, this 'silent disease' can cause trachoma, infertility, tubal pregnancy and other urinogenital disorders if left untreated. A brief overview of the disease, treatment options and preventive strategies would give a better insight of this medical condition.

Chlamydia trachomatis (Life Cycle)

Chlamydia trachomatis is a parasitic bacterium that cannot produce its own ATP and hence depends on host cells for its energy needs. It is an intracellular parasite which is mainly found to affect humans. This bacterium has a unique morphology that protects it from the immunological response of the human host. An important characteristic of this bacterium is that its life cycle is composed of two distinct stages known as the 'elementary bodies' and the 'reticulate bodies'. The elementary bodies are 0.3-0.4 µm sized spore like forms of the organism which possess a thick outer membrane with disulphide bonds. This protective outer wall provides the elementary bodies protection from the external conditions and also prevents the phagolysosome fusion in phagocytes and hence helps evade the typical phagocyte 'engulf and digest'mechanism. The cell wall has a lipopolysaccharide layer and there is no peptidoglycan. These elementary bodies attach themselves to the receptor cites on the surface of the host cells and induce endocytosis.

Once inside the host cell the elementary bodies evolve or change into a vegetative form known as the 'reticulate bodies'. Thus the reticulate form is actually the intracellular form of the bacterium. The reticulate form undergoes continuous replication by binary fission. These reticulate bodies do not have any distinct cell wall and are only identified as inclusions in the host cell. Once the fission is completed (approximately one division every 2 to 3 hours) the reticulate bodies reorganize into the elementary form and are thrown out of the cell by means of exocytosis. It is estimated that each cellular inclusion may contain 100-500 elementary bodies that are released out of the cell. Thus, by means of this unique two stage process Chlamydia trachomatis continues to multiply inside the host rapidly with minimal interference from the body's immune system. [Andrea DeMets]

Symptoms and Transmission

Chlamydia is a silent disease with very little early symptoms. Leukocyte esterase tests, DNA probes and ELISA tests can be used to confirm the infection. The disease is primarily transmitted through infected secretions. Being a sexually transmitted disease it is spread via intercourse and it mainly affects the mucosal membranes like cervix, urethra, rectum, conjunctiva and the throat. When the infected secretions are spread to the eyes by means of hands it may lead to trachoma. It is to be noted that trachoma is a serious problem and around 7 to 9 million people worldwide have acquired blindness due to Chlamydia. Reactive arthritis is also an observed condition in some patients. In women the main symptoms include increased or continuous vaginal discharge, pelvic pain, vaginal bleeding etc. Infected men may have white or yellowish discharge from the urethra accompanied by a burning sensation during urination. In acute cases lymphogranuloma venereum (swelling of the lymph nodes) may manifest leading to proctitis or other rectal discomforts. [University of South Carolina]

Treatment for Chlamydia

Chlamydia is totally curable with appropriate medical intervention. Many different kinds of antibiotics are found to be effective in the treatment of the disease. Azithromycin is the currently preferred choice of antibiotic and is useful as an effective single dose treatment. Doxycycline is another antibiotic which is prescribed for a course of one week. However this drug is considered unsafe as a treatment method for pregnant women. Erythromycin is a common antimicrobial medicine which is effective in treating Chlamydia and is also the preferred drug for treating pregnant women. Other antibiotics such as tetracycline, ofloxacin and amoxicillin are also effective against Chlamydia trachomatis. [Larry I Lutwick] Due to the action of the antibiotics naturally occurring beneficial intestinal bacteria will also be destroyed and hence to compensate for this live cultures of Lactobacillus acidophillus, L. bifidus are prescribed. Further, long-term courses of antibiotics can cause fungal and vaginal yeast infections in women which have to be treated appropriately. Typically Nizoral, Diflucan, Mycelex and other anti-yeast creams are prescribed. [Garth L. Nicolson]

Prevention Strategies