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Trichuriasis, also known as whipworm infection, is an infection by the parasitic worm ''Trichuris trichiura'' (whipworm). If infection is only with a few worms, there are often no symptoms.〔 In those who are infected with many worms, there may be abdominal pain, tiredness and diarrhea.〔 The diarrhea sometimes contains blood.〔 Infections in children may cause poor intellectual and physical development. Low red blood cell levels may occur due to loss of blood.〔 The disease is usually spread when people eat food or drink water that contains the eggs of these worms.〔 This may occur when contaminated vegetables are not fully cleaned or cooked.〔 Often these eggs are in the soil in areas where people defecate outside and where untreated human feces is used as fertilizer.〔 These eggs originate from the feces of infected people.〔 Young children playing in such soil and putting their hands in their mouths also become infected easily.〔 The worms live in the large bowel and are about four centimetres in length.〔 Whipworm is diagnosed by seeing the eggs when examining the stool with a microscope. Eggs are barrel-shaped. Trichuriasis belongs to the group of soil-transmitted helminthiasis. Prevention is by properly cooking food and hand washing before cooking. Other measures include improving access to sanitation such as ensuring use of functional and clean toilets〔 and access to clean water. In areas of the world where the infections are common, often entire groups of people will be treated all at once and on a regular basis. Treatment is with three days of the medication: albendazole, mebendazole or ivermectin. People often become infected again after treatment. Whipworm infection affects about 600 to 800 million people worldwide.〔 It is most common in tropical countries.〔 In the developing world, those infected with whipworm often also have hookworms and ascariasis infections.〔 They have a large effect on the economy of many countries. Work is ongoing to develop a vaccine against the disease.〔 Trichuriasis is classified as a neglected tropical disease. ==Signs and symptoms== * Light infestations (<100 worms) frequently have no symptoms. * Heavier infestations, especially in small children, can present gastrointestinal problems including abdominal pain and distension, bloody or mucus-filled diarrhea, and tenesmus (feeling of incomplete defecation, generally accompanied by involuntary straining). While damage may be done to the GI tissue and appendicitis may be brought on (by damage and edema of the adjacent lumen) if there are large numbers of worms or larvae present, it has been suggested that the embedding of the worms into the ileo-cecal region may also make the host susceptible to bacterial infection. A severe infection with high numbers of embedded worms in the rectum leads to edema, which can cause rectal prolapse, although this is typically only seen in small children. The prolapsed, inflamed and edematous rectal tissue may even show visible worms. * Growth retardation, weight loss, nutritional deficiencies, and anemia (due to long-standing blood loss) are also characteristic of infection, and these symptoms are more prevalent and severe in children. It does not commonly cause eosinophilia. * Coinfection of Trichuris trichiura with other parasites is common and with larger worm burdens can cause both exacerbation of dangerous trichuriasis symptoms such as massive gastrointestinal bleeding (shown to be especially dramatic with coinfection with Salmonella typhi) and exacerbation of symptoms and pathogenesis of the other parasitic infection (as is typical with coinfection with Schistosoma mansoni, in which higher worm burden and liver egg burden is common). Parasitic coinfection with HIV/AIDS, tuberculosis, and malaria is also common, especially in Sub-saharan Africa, and helminth coinfection adversely affects the natural history and progression of HIV/AIDS, tuberculosis, and malaria and can increase clinical malaria severity. In a study performed in Senegal, infections of soil-transmitted helminths like Trichuris trichiura (as well as schistosome infections independently) showed enhanced risk and increased incidence of malaria. * Heavy infestations may have bloody diarrhea. * Long-standing blood loss may lead to iron-deficiency anemia. * Rectal prolapse is possible in severe cases. * Vitamin A deficiency may also result due to infection. Mechanical damage to the mucosa may occur as well as toxic or inflammatory damage to the intestines of the host. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「trichuriasis」の詳細全文を読む スポンサード リンク
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