鉤端螺旋體病

title: 病因与诊断.
content: 钩端螺旋体中共有10种能感染人类。例如牛、猪、犬等家畜与猫、狗、鼠等野生动物都可能传染钩端螺旋体病,最常见的宿主是啮齿目动物,特别是野鼠类(黑线姬鼠、 黄毛鼠、黄胸鼠、褐家鼠等)。动物可能在感染钩端螺旋体后本身不发病,但造成肾脏慢性感染,并经由尿液大量排菌,钩端螺旋体病通常由染病动物的尿液或被染病动物尿液污染的水传播,当尿液或被污染的水接触到皮肤上的伤口或眼睛、口腔、鼻腔或阴道等黏膜表面时便可能会感染。进食受污染的肉类或奶品也可能感染,而在牧场或屠房等地方工作的人士,受感染风险会较高。在发展中国家,钩端螺旋体病最常感染城市中的贫民或农民,在已开发国家中则常感染在气候暖湿地区从事户外活动的人。临床特点早期为钩端螺旋体败血症,中期为各器官损害及功能障碍,后期则为各种变态反应并发症。由于患者的初期表现多为突发性发烧、头痛、畏寒、肌肉疼痛及结膜充血涨红,这些症状也是常见于其他各种感染症,例如登革热、恙虫病、或是流行性感冒。所以并不易由临床症状做区分,因此治愈重点是患者提供各种资讯如旅游史或职业,以及医师及早考虑此病之可能并且快速用药及检验。确诊钩端螺旋体病的方式包括在血液(头7天)、脑脊液(第4-10天)或尿液(10天后)中培养出钩端螺旋体、在前述数种体液中测得钩端螺旋体的脱氧核糖核酸、以及测得针对钩端螺旋体感染的抗体(恢复期血清相比早期血清抗体效价升高4倍或以上)。
title: 预防与治疗.
content: 预防钩端螺旋体病的方式包括使用防护装备以避免与可能染病的动物接触、与动物接触后确实清洗、以及减少居所与工作场所的啮齿类动物。通过改造农田排灌系统、退耕还湖可以有效减少鼠类栖息地及控制洪水型钩体病流行;提倡圈养猪也是其中一环。疫苗接种应在流行期之前进行(通常为每年4-5月份),接种后约需1个月才能产生有效抗体。对于已发生钩体病流行的人群接种疫苗,来不及产生抗体,效果较差,故多采取口服去氧羟环素(强力霉素),200mg于一周内1次或分2次服用。旅游时有时会服用抗生素,比如去氧羟四环素(强力霉素),以预防钩端螺旋体病,但是否有效果尚不确定。有几类的钩端螺旋体已经有可让动物施打的疫苗,替动物施打疫苗也同时能减少钩端螺旋体病传染给人类的风险。治疗钩端螺旋体病的抗生素有去氧羟四环素、青霉素、以及头孢曲松等。魏氏病和严重肺出血症候群等重症的死亡率即使经治疗仍达10%以上至50%不等。临床上若有人的职业或是休闲活动是和野外相关,例如农夫、矿工、畜牧业者或是屠宰场工作者及最近在野外游泳、露营者有发烧之情形,则需小心可能是感染钩端螺旋体经潜伏期约四至十九天(通常为十天)后发病了。钩端螺旋体病的治疗仰赖抗生素之使用,青霉素(penicillin G)为首选,庆大霉素次之,红霉素、去氧羟四环素或四环霉素也可使用。然而预防胜于治疗,妥善处理家畜及宠物之排泄物,避免环境受到污染,经常暴露于病原环境场所之工作者,如兽医、屠宰场工人、畜牧业者等应戴手套以免感染,野外活动接触动物后应立即洗手,并避免在野外水池中游泳,才是避免得到这个可能会造成肾衰竭、黄疸、乃至于致死却又难以诊断的疾病的方法。
title: 流行病学.
content: 在世界各地,不论乡村或城市,已开发或开发中国家,除了极地之外,皆有钩端螺旋体病发生。此病易发生于野外经常接触可能受感染动物排泄物污染之水源或屠体组织之工作者,如:农民、矿工、兽医、畜牧业者、渔民及军队等;于人群中爆发流行原因,为接触到受感染动物污染之水源(例:河流、湖水等),尤其是在污染区从事野外活动-游泳、露营、运动等。洪水泛滥后常见爆发性流行。  估计每年有七百万到一千万人感染钩端螺旋体症,因而死亡的人数则不明。钩端螺旋体病在热带地区最常见,但在其他地区也可能出现。大流行可能在发展中国家的贫民窟中发生。感染钩端螺旋体病的动物可能没有症状、只有轻微症状、或是有严重的症状,症状的严重程度也和动物种类有关。

Summary: 钩端螺旋体病(,又译细螺旋体症)简称钩体病,是一种人畜共通传染病,由类细菌引起的感染。患者可能无症状或表现轻度头痛、肌肉疼痛、发热到严重的肺出血或脑膜炎。如果此感染造成黄疸、肾衰竭或出血,此时疾病又称为威尔氏病(英语:Weil's disease)。如果造成肺部大量出血则称作严重肺出血症候群。钩端螺旋体病在1886年的德国由威尔氏发现。该病曾于中国大陆有过广泛分布,然而,据2016年数据统计,全中国大陆总计报告仅354例。

Leptospirosis: Leptospirosis is a blood infection caused by the bacteria "Leptospira". Signs and symptoms can range from none to mild (headaches, muscle pains, and fevers) to severe (bleeding in the lungs or meningitis). Weil's disease, the acute, severe form of leptospirosis, causes the infected individual to become jaundiced (skin and eyes become yellow), develop kidney failure, and bleed. Bleeding from the lungs associated with leptospirosis is known as "severe pulmonary haemorrhage syndrome". More than ten genetic types of "Leptospira" cause disease in humans. Both wild and domestic animals can spread the disease, most commonly rodents. The bacteria are spread to humans through animal urine, or water and soil contaminated with animal urine, coming into contact with the eyes, mouth, nose or breaks in the skin. In developing countries, the disease occurs most commonly in farmers and low-income people who live in areas with poor sanitation. In developed countries, it occurs during heavy downpours and can affect those involved in outdoor activities in warm and wet areas. Diagnosis is typically by testing for antibodies against the bacteria or finding bacterial DNA in the blood. Efforts to prevent the disease include protective equipment to block contact when working with potentially infected animals, washing after contact, and reducing rodents in areas where people live and work. The antibiotic doxycycline is effective in preventing leptospirosis infection. Human vaccines are of limited usefulness; vaccines for other animals are more widely available. Treatment when infected is with antibiotics such as doxycycline, penicillin, or ceftriaxone. The overall risk of death is 5–10%. However, when the lungs are involved, the risk of death increases to the range of 50–70%. It is estimated that one million people worldwide are infected by leptospirosis every year, causing about 58,900 deaths. The disease is most common in tropical areas of the world but may occur anywhere. Outbreaks may arise after heavy rainfall. The disease was first described by physician Adolf Weil in 1886 in Germany.