诺如病毒

title: 发现到命名.
content: 1968年,在美国俄亥俄州的诺瓦克(Norwalk)发生了流行性肠胃炎,从患者的粪便里检出病毒,被称为诺瓦克病毒(Norwalk virus)。  1972年,通过电子显微镜观察发现其形态呈小型、圆状,被认为是小圆结构病毒(Small Round Structured Virus: SRSV)的一种。之后,从非细菌性急性胃肠炎患者身上接连发现与诺沃克病毒相似的小圆状结构病毒,被称为「类诺沃克病毒」(Norwalk-like viruses)或小圆结构病毒。另外在日本还发现了札幌病毒(Sapporo virus)。  这种引起非细菌性急性胃肠炎的小圆结构病毒有两种,即类诺沃克病毒和类札幌病毒(Sapporo-like viruses)。2002年8月,在巴黎召开的第12届国际病毒学会议(International Congress of Virology)上,这两种病毒按发现地点分别被正式命名为「诺如病毒」(Norovirus)和「札幌病毒」(Sapovirus)。  诺如病毒又按遗传基因分为基因群I和基因群II。基因群I(genogroup I)里有诺如病毒、南安普顿病毒(Southampton virus)、沙漠风暴病毒(Desert Shield virus);基因群II(genogroup II)里有雪山病毒(Snow Moun)大陆旧译「诺罗病毒」,后改为「诺如病毒」;香港旧译「诺沃克病毒」,2009年起官方更改译名为「诺如病毒」。台湾将之译成「诺罗病毒」。
title: 诺罗病毒主要症状.
content: 一般症状主要有腹痛、腹泻、呕吐、低烧、全身肌肉酸痛等。症状一般维持12至60小时后自行消退,但病毒的排泄会延续2星期左右。如腹泻厉害,容易发生脱水、休克等症状。
title: 潜伏期.
content: 潜伏期通常为24至48小时。
title: 传播途径.
content: 诺沃克病毒的感染全年均可发生,尤以冬季较多。  传播途径主要有感染性食物中毒和传染性胃肠炎。生食海贝类及牡蛎等水生动物是该病毒的主要传播途径,也会从非细菌性急性胃肠炎患者的呕吐物及粪便,或者干燥之后通过尘埃感染。  由于该病毒可以在体外环境存活达三个星期之久,而只需吞咽极少量(十来个病毒)就可能感染,所以该病毒传染性很强,间接接触是长期被忽略的传染渠道。比如患者便后或呕吐后洗手不够彻底,则会污染门把手,水龙头,遥控器,毛巾,衣物等,健康人接触过这些物品再手拿东西吃,或准备食物,就可能感染。  预防的关键在于患者和健康人群都频繁地用肥皂和热水认真洗手,特别是进食前和如厕后。被患者便后或呕吐后接触过的物品和台面,要用含氯漂白剂清洁。  患者的唾液也含有该病毒,不能共享餐具和饮食。患者一般三五天后恢复健康,传染性减低。但物品上所带的病毒可以存活两三个星期,被污染的水源里的病毒可以存活更长。  患者在痊愈后几个月之内对该病毒有免疫力,但之后免疫力会消失。
title: 医治方法.
content: 此病以缓和相关的症状为治疗,患者需勤于使用肥皂洗手(诺罗病毒对于酒精类消毒剂有抵抗能力,因此酒精的效果不佳)。目前尚无疫苗可预防治疗。
title: 参考资料.
title: 病毒案例.
content: 25.https://www.youtube.com/watch?v=yxr4By49RMM

Summary: 诺罗病毒(英语:Norovirus,NV, 或 Winter Vomiting Bug),又称为诺沃克病毒、诺如病毒或脓融病毒,是一种引起非细菌性急性胃肠炎的病毒。诺罗病毒的特征是感染人口密度较高和卫生环境差的地方,如邮轮。诺罗病毒主要由粪口途径传染,即食物被充满病毒的粪便污染所致,在人口密度高的地方也可能透过飞沫传染。

Norovirus: Norovirus, sometimes referred to as the winter vomiting bug, is the most common cause of gastroenteritis. Infection is characterized by non-bloody diarrhea, vomiting, and stomach pain. Fever or headaches may also occur. Symptoms usually develop 12 to 48 hours after being exposed, and recovery typically occurs within 1 to 3 days. Complications are uncommon, but may include dehydration, especially in the young, the old, and those with other health problems. The virus is usually spread by the fecal–oral route. This may be through contaminated food or water or person-to-person contact. It may also spread via contaminated surfaces or through air from the vomit of an infected person. Risk factors include unsanitary food preparation and sharing close quarters. Diagnosis is generally based on symptoms. Confirmatory testing is not usually available but may be performed during outbreaks by public health agencies. Prevention involves proper hand washing and disinfection of contaminated surfaces. Alcohol-based hand sanitizers can be used in addition but are less effective than hand washing. There is no vaccine or specific treatment for norovirus. Management involves supportive care such as drinking sufficient fluids or intravenous fluids. Oral rehydration solutions are the preferred fluids to drink, although other drinks without caffeine or alcohol can help. Norovirus results in about 685 million cases of disease and 200,000 deaths globally a year. It is common both in the developed and developing world. Those under the age of five are most often affected, and in this group it results in about 50,000 deaths in the developing world. Norovirus infections occur more commonly during winter months. It often occurs in outbreaks, especially among those living in close quarters. In the United States, it is the cause of about half of all foodborne disease outbreaks. The virus is named after the city of Norwalk, Ohio, where an outbreak occurred in 1968.