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Leptospirosis (also known as field fever, rat catcher's yellows, and pretibial fever among others names) is an infection caused by corkscrew-shaped bacteria called ''Leptospira''. Signs and symptoms can range from none to mild such as headaches, muscle pains, and fevers; to severe with bleeding from the lungs or meningitis.〔 If the infection causes the person to turn yellow, have kidney failure and bleeding, it is then known as Weil's disease. If it causes lots of bleeding from the lungs it is known as severe pulmonary haemorrhage syndrome.〔 Up to 13 different genetic types of ''Leptospira'' may cause disease in humans. It is transmitted by both wild and domestic animals.〔 The most common animals that spread the disease are rodents. It is often transmitted by animal urine or by water or soil containing animal urine coming into contact with breaks in the skin, eyes, mouth, or nose.〔〔(【引用サイトリンク】url=http://www.cdc.gov/leptospirosis/infection/index.html )〕 In the developing world the disease most commonly occurs in farmers and poor people who live in cities.〔 In the developed world it most commonly occurs in those involved in outdoor activities in warm and wet areas of the world.〔 Diagnosis is typically by looking for antibodies against the bacteria or finding its DNA in the blood. Efforts to prevent the disease include protective equipment to prevent contact when working with potentially infected animals, washing after this contact, and reducing rodents in areas people live and work.〔 The antibiotic doxycycline, when used in an effort to prevent infection among travellers, is of unclear benefit.〔 Vaccines for animals exist for certain type of ''Leptospira'' which may decrease the risk of spread to humans.〔 Treatment if infected is with antibiotics such as: doxycycline, penicillin, or ceftriaxone.〔 Weil's disease and severe pulmonary haemorrhage syndrome result in death rates greater than 10% and 50%, respectively, even with treatment.〔 It is estimated that seven to ten million people are infected by leptospirosis a year. The number of deaths this causes is not clear.〔 The disease is most common in tropical areas of the world but may occur anywhere.〔 Outbreaks may occur in slums of the developing world.〔 The disease was first described by Weil in 1886 in Germany.〔 Animals who are infected may have no symptoms, mild symptoms, or severe symptoms.〔 Symptoms may vary by the type of animal.〔 In some animals ''Leptospira'' live in the reproductive tract, leading to transmission during mating. ==Signs and symptoms== Leptospiral infection in humans causes a range of symptoms, and some infected persons may have no symptoms at all. Leptospirosis is a biphasic disease that begins suddenly with fever accompanied by chills, intense headache, severe myalgia (muscle ache), abdominal pain, conjunctival suffusion (red eye), and occasionally a skin rash. The symptoms appear after an incubation period of 7–12 days. The first phase (acute or septicemic phase) ends after 3–7 days of illness. The disappearance of symptoms coincides with the appearance of antibodies against ''Leptospira'' and the disappearance of the bacteria from the bloodstream. The patient is asymptomatic for 3–4 days until the second phase begins with another episode of fever.〔 The hallmark of the second phase is meningitis (inflammation of the membranes covering the brain). 90 percent of cases of the disease are mild leptospirosis. The rest experience severe disease, which develops during the second stage or occurs as a single progressive illness. The classic form of severe leptospirosis is known as Weil's disease, which is characterized by liver damage (causing jaundice), kidney failure, and bleeding. Additionally, the heart and brain can be affected, meningitis of the outer layer of the brain, encephalitis of brain tissue with same signs and symptoms; and lung affected as the most serious and life-threatening of all leptospirosis complications. The infection is often incorrectly diagnosed due to the nonspecific symptoms. Other severe manifestations include extreme fatigue, hearing loss, respiratory distress, and azotemia. 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「leptospirosis」の詳細全文を読む スポンサード リンク
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