Table of ContentsAbout STDsWho Gets STDsChlamydia (Klah-Mid-Ee-Uh)How to Get ItHow It's TransmittedWhat It Looks Like and What the Symptoms AreHow to Get Tested to detect itCurrent treatments Diagnosis of symptoms of treatable STDs? Outcome of treatment if left untreatedChlamydia cases in Wisconsin 1965-1991 (cases per 100,000 people, per year, by sex and age)History and biological contextVirulence factorsModel of cell wall or envelope Chlamydia (after outbreak)VaccinesLife cycleThe infectious life cycle of Chlamydia (after RC Barnes)Transmission and symptomsDiagnostic testsDNA probes: uses DNA complementary to specific ribosomal RNA sequencesIntracellular inclusions of C. trachomatis (after RC Barnes)TreatmentPreventionPersonal StrategiesCommunity StrategiesRole of Health Care ProvidersWisconsin Control ProgramChlamydia Social IssuesAbout STDs “STDs” (sexually transmitted diseases) is a broad term for up to 20 different diseases, all transmitted sexually - usually through the exchange of bodily fluids such as semen, vaginal secretions and blood. STDs can also be passed from mothers to their babies. You can get certain STDs, like herpes, from kissing, caressing, or touching infected areas – and not just through sex. Some STDs just make you uncomfortable. Some are more dangerous: if left untreated, they can cause permanent damage that leaves you blind, brain damaged, or unable to have children. The first, HIV (human immunodeficiency virus) disease, often leads to AIDS (acquired immunodeficiency syndrome), which can lead to death. Say no to plagiarism. Get a tailor-made essay on “Why violent video games should not be banned”?Get the original essay Some of the most common STDs include chlamydia, herpes, gonorrhea, genital warts, syphilis, hepatitis B, crabs and trichomoniasis.STDs are becoming more common in the United States today. This is worrying news because STDs are also easy to prevent. This book will tell you about STDs and describe how you can take simple steps to protect yourself and your partners. Who gets STDs? Anyone who has sex can contract a sexually transmitted disease. And this is the case for millions of people. According to the federal Centers for Disease Control, more than 4 million Americans, both men and women, contract chlamydia each year. Genital herpes affects approximately 30 million Americans, with up to 500,000 new cases each year. One million cases of gonorrhea are reported each year in the United States, and an estimated one million additional cases go unreported each year. Genital warts affect at least 3 million American men and women each year. And syphilis, long thought to be in decline, is on the rise. In 1989, syphilis affected more than 100,000 Americans, and the number is increasing. It is estimated that between 500,000 and 1 million Americans are infected with hepatitis B. Trichomoniasis affects at least 3 million Americans each year. The Centers for Disease Control estimates that more than 1 million Americans are infected with HIV (the AIDS virus). Before you start reading about the signs of sexually transmitted diseases, you may find it helpful to know the meaning of certain terms. These diagrams show the genital areas of men and women and identify the parts of the genitals. You can go thererefer when reading about STDs.Chlamydia (Klah-Mid-Ee-Uh)How to get itYou get chlamydia by having sex with an infected person. If you and your partner do not use condoms, you are more likely to contract chlamydia. How it is spread Chlamydia is spread when germs (bacteria) are passed from one person to another during sex. What it looks like and what the symptoms are Sometimes chlamydia causes no visible signs. But other times it does. If there are visible signs, you will notice them within 1 to 3 weeks after having sex with an infected person. Men may see discharge from the penis or a slight crust at the tip of the penis. Women may see vaginal discharge or feel stomach pain. Both men and women may experience pain or a burning sensation when urinating. How to get tested To find out if you have chlamydia, your doctor or health care professional will take a small amount of fluid from the penis or vagina and send it to a laboratory. to examine. It will take a few days to get the result. Current Treatments Chlamydia is treatable. If you have it, you will be given pills that kill chlamydia germs. What will happen to you if you don't get treatment? If you don't get treatment for chlamydia, you could get serious infections. Women may suffer from pelvic inflammatory disease (PID), which can prevent them from having children. Symptoms Std Diagnosis Can it be treated? Treatment outcome if left untreated Gonorrhea Pain or burning when urinating, yellow discharge Laboratory examination of fluid from infected area Yes Antibiotic pills that kill bacteria Pelvic infection, PID, infertility Chlamydia trachomatis by Andrea DeMets, Department of bacteriology from the University of Wisconsin-Madison. Chlamydia is the most common sexually transmitted disease in the United States. There are around four million cases per year, most affecting men and women under the age of 25. The direct and indirect costs of chlamydia (mainly costs related to complications) total $24 billion per year. This is likely an underestimate, since half of people with chlamydia also have gonorrhea. Therefore, costs related to the diagnosis and treatment of the latter sexually transmitted disease must be included. Chlamydia cases in Wisconsin from 1965 to 1991 (cases per 100,000 people, per year, by sex and age) History and biological context Chlamydia is caused by the bacterium Chlamydia trachomatis. The word chlamys comes from Greek and means “cloak draped around the shoulder”. This describes how intracytoplasmic inclusions caused by the bacteria are “draped” around the nucleus of the infected cell. Because the symptoms of the disease resemble other conditions, chlamydia was only recently recognized as a sexually transmitted disease. Isolation from embryonated eggs in 1957 and from cell cultures in 1963 confirmed its existence as a bacteria. However, because this organism is an obligate intracellular parasite that exclusively infects humans (it cannot synthesize its own ATP or grow on an artificial medium), it was once thought to be a virus. Due to the unique development cycle of Chlamydia, it has been taxonomically classified in a distinct order. We thus find it with the other well-known intracellular parasites, the rickettsiae, in diagnostic manuals. Chlamydia has a genome of approximately 500 to 1,000 kilobases andcontains both RNA and DNA. The organism is also extremely sensitive to temperature and must be refrigerated at 4°C as soon as a sample is obtained. Virulence factors Many factors contribute to the pathogenicity of Chlamydia trachomatis. Chlamydia colonization begins with attachment to sialic acid receptors on the eyes, throat, or genitals. It persists in body sites inaccessible to phagocytes, T lymphocytes and B lymphocytes. It also exists in the form of 15 different serotypes. These serotypes cause four major diseases in humans: endemic trachoma (caused by serotypes A and C), sexually transmitted diseases and inclusion conjunctivitis (caused by serotypes D and K), and lymphogranuloma venereum (caused by serotypes L1, L2 and L3). Endemic trachoma leads to blindness, while inclusion conjunctivitis is associated with the sexually transmitted form and does not lead to blindness. Its unique cell wall structure is another virulence factor. Studies reveal that Chlamydia, thanks to its cell wall, is able to inhibit the fusion of phagolysosomes in phagocytes. The cell wall is proposed to be Gram-negative in that it contains a lipopolysaccharide outer membrane, but it lacks peptidoglycan in its cell wall. This lack of peptidoglycan results in the inability to detect muramic acid and antibodies directed against it. It may, however, contain a carboxylated sugar other than muramic acid. The proposed structure consists of a major outer membrane protein cross-linked by disulfide bonds. It also contains cysteine-rich proteins (CRP) which may be the functional equivalent of peptidoglycan. This unique structure allows intracellular division and extracellular survival (Hatch 1996).Chlamydial cell wall or envelope model (after Hatch)VaccinesThe surface of chlamydia does not contain proteins distinctive enough to induce a full immune response. The cell wall contains an exoglycolipid antigen which induces a weak immune response (for unknown reasons, the immune response is weaker to carbohydrate antigens). It's the basis of a recent vaccine developed by researchers at Johns Hopkins University. Researchers develop a protein version of the antigen by injecting C. trachomatis into mice, isolating and amplifying the antibodies produced, and then using these antibodies to “cast” a protein resembling the exoglycolipid antigen (Coghian 1996). The next step is to adapt the procedure to humans.Life cycleThe life cycle of C. trachomatis consists of two stages: the elementary body and the reticulate body. The elementary body is the dispersion form and is analogous to a spore. It measures approximately 0.3 µm in diameter and induces its own endocytosis upon exposure to target cells. It is this form that prevents phagolysosomal fusion and thus allows intracellular survival. Once inside the endosome, the glycogen produced causes the elementary body to “germinate” in the vegetative form, the reticulate body. This form divides by binary fission approximately 2 to 3 hours per generation. Its incubation period is 7 to 21 days in the host. It does not contain a cell wall and (when stained with iodine) is detected as an inclusion in the cell. After division, the reticular body returns to its elementary form and is released by the cell by exocytosis. A phagolysosome typically produces 100 to 1,000 elementary bodies. The infectious life cycle of Chlamydia (after RC Barnes) Transmission and symptoms Chlamydia is transmitted only by infected secretions. It mainly infects the mucous membranes, suchas the cervix, rectum, urethra, throat and conjunctiva. It is spread primarily through sexual contact and manifests as a sexually transmitted disease. The bacteria is not easily transmitted between women, so the STD is transmitted primarily through heterosexual or homosexual male contact. However, infected discharge from the genitals to the hands and possibly the eyes can cause trachoma. The symptoms due to this contact are quite variable. In fact, 75% of women and 25% of men with Chlamydia have no symptoms. In women, symptoms include increased vaginal discharge, burning during urination, irritation of the area around the vagina, bleeding after sex, lower abdominal pain, and abnormal vaginal bleeding. Infection in women usually begins at the cervix. In men, nongonococcal urethritis is the main symptom. This includes clear, white, or yellow discharge from the urethra, burning and pain during urination, and tingling or itching sensations. Another infection caused by C. trachomatis, lymphogranuloma venereum, is characterized by swelling of the lymph nodes in the groin area. In men this can lead to proctitis and in women it can lead to rectal stricture. The primary stage is detected in the form of small ulcers or blisters which usually heal without leaving scars. The secondary stage, called “superative lymphadenopathy”, is characterized by chills, fever and arthralgia. The large area of ​​swelling in the groin is called a bubo. Finally, the tertiary stage is where rectal stricture or drainage of the sinuses occurs. Diagnostic Tests Detection of the bacteria can be done using non-culture and culture tests. Non-culture tests include the following: Fluorescent monoclonal antibody test: detects either the major outer membrane protein or LPS enzyme immunoassay: detects a colored product converted by an enzyme linked to an antibody DNA probes: uses the complementary DNA of specific ribosomal RNA sequencesRapid tests Chlamydia: uses antibodies against LPSesterase of leukocytes: detects enzymes produced by leukocytes containing the bacteria in urineAmplification of nucleic acids by polymerase chain reaction and chain ligase Reactions are also in progress of experimentation. Unfortunately, some non-culture tests are not specific and therefore cause false positive results. Likewise, antibodies can cross-react with non-chlamydial species. Culture tests identify intracytoplasmic inclusions in cells stained with monoclonal fluorescent antibodies. The cells are then expanded on cyclohexamide-treated McCoy cells (a mouse cell line readily infected by the bacteria). Unlike non-culture tests, culture tests are 100% specific. The disadvantages are that it takes 3-7 days to get results, is technically difficult, requires special transportation, and is prone to contamination. Likewise, sample collection, if delayed for more than 48 hours, requires storage at -70°C. Since Chlamydia are normally found in association with normal flora, samples should be treated with gentamycin to kill other microorganisms. Dead microorganisms or the effect of gentamycin on chlamydia may bias the results. Intracellular inclusions of C. trachomatis (after RC Barnes) TreatmentThe treatment of chlamydia is carried out with various.