世卫组织：地球最严重的9种病毒，包括一种中日韩新发现病毒

您已经听说过埃博拉病毒和寨卡病毒，但还有许多危险病毒尚未成为头条新闻。不久的将来可能引起严重疫情暴发。世卫组织召集了科学家和公共卫生专家小组，讨论了最有可能在不久的将来引起严重疫情暴发的主要病原体。这些是没有疫苗且几乎没有治疗方法的病毒。

下面是这些疾病的概述以及它们如此可怕的原因。

克里米亚-刚果出血热

根据美国疾病控制与预防中心（CDC）的数据，克里米亚-刚果出血热（CCHF）主要由蜱虫和牲畜传播，于1944年首次出现在克里米亚，并以克里米亚出血热命名。后来，当它在1969年被确认为刚果病的罪魁祸首时，其名称更改为克里米亚-刚果出血热。根据世界卫生组织报告，CCHF暴发的致死率高达40％，且没有疫苗。

症状突然发作，包括头痛，高烧，呕吐以及背部，关节和胃痛。随着疾病的继续，可能会出现严重的瘀伤和流鼻血，以及面部，口腔和喉咙的出血。

在某些情况下，由于与被感染的血液或体液紧密接触，病毒可在人与人之间传播。CCHF在许多地方都有发现，包括非洲，中亚，中东，东欧和南欧以及印度。

埃博拉病毒

已知的第一例埃博拉病例，也称埃博拉出血热，出现在1976年。据世界卫生组织报道，尽管中非偏远村庄在热带雨林附近暴发了早期疫情，但最近的暴发也发生在城市地区。这种严重的疾病是由一种病毒引起，这种病毒从野生动物传播到人，然后在人与人之间传播。平均死亡率为50％，但在某些暴发中死亡已高达90％。

目前尚无埃博拉疫苗，但正在评估临床试验。症状从发烧，呕吐到出血和虚弱不等。康复取决于良好的支持治疗和患者的免疫系统。

马尔堡出血热

60年代在欧洲发生的两起神秘疫情可追溯到处理从乌干达进口的非洲猴子的实验室工作人员。该病毒是埃博拉病毒家族的一种线状病毒，以德国首次发现该病毒的城市马尔堡（Marburg）命名。该病毒的天然宿主被认为是翼足类的果蝠。该病毒从蝙蝠传播到人，然后通过人与人的接触传播。

症状包括高烧，剧烈头痛和肌肉疼痛，突然开始并迅速发展，包括胃肠道疾病，极度嗜睡和出血。在致命病例（高达88％的病例）中，死亡发生在症状开始后不到10天。

没有可用的疫苗或治疗方法。

世界卫生组织已报告在安哥拉，刚果民主共和国，肯尼亚，南非和乌干达暴发了疫情。

拉沙热

据世界卫生组织报道，约有80％的人感染了拉沙病毒后从未出现症状。这就是很难检测到该病毒的原因。该病毒是一种人畜共患病，可通过接触被鼠尿或粪便污染的食物或生活用品传播给人们。但是它也可以通过被感染的血液或体液在人与人之间传播。

对于那些有症状的人，他们通常是轻度的，包括低烧和整体虚弱。症状较严重的人可能会眼睛，牙龈和鼻子流血，并出现呕吐，呼吸窘迫，面部肿胀，耳聋和严重疼痛。

仅约1％的拉沙病毒感染会导致死亡。

MERS和SARS冠状病毒

中东呼吸综合征（MERS）和严重急性呼吸综合征（SARS）是冠状病毒家族的一部分——冠状病毒通常引起上呼吸道疾病。尽管病毒的传播似乎来自受感染的骆驼，但两种疾病都容易通过人打喷嚏和咳嗽传播。

据美国疾病预防控制中心（CDC）称，SARS于2003年首次在亚洲报道，但全球疫情迅速得到遏制，自2004年以来未再报告任何病例。然而，MERS于2012年首次报道，此后已传播到其他国家。据世界卫生组织称，约有36％的人曾报告过MERS死亡。

目前没有疫苗或治疗方法。

尼帕病毒和裂谷热

世界卫生组织最近将这两种人畜共患病命名为一些最危险的新兴病原体，这些病原体可能导致严重暴发，死亡率高达75％。1998年马来西亚养猪户患病时首次发现尼帕病毒感染。作为回应，超过一百万头猪被安乐死。在印度和孟加拉国以后的暴发中，没有明显的宿主。据美国有线电视新闻网报道，该病毒于2018年在印度再次出现并致死17人。症状包括呼吸问题和精神错乱。

裂谷热于1931年在肯尼亚的绵羊养殖场首次发现，此后在非洲大部分地区暴发。该疾病是通过处理被感染的动物组织，喝被感染的牛奶或被叮咬的蚊子传播的。没有人与人之间传播的案例记录。症状包括发烧，肌肉疼痛和头痛。一小部分患者患有眼部疾病或脑部炎症。

尼帕病毒感染或裂谷热都没有疫苗。

基孔肯雅病毒

基孔肯雅病毒（发音为“goon-goon-ya”）由埃及伊蚊，埃及白纹伊蚊（俗称亚洲虎蚊）传播给人们。就是导致我们登革热的昆虫。被世界卫生组织确定为“严重”，可引起发烧和严重的关节疼痛，有时使人衰弱。其他症状包括肌肉疼痛，头痛，恶心，疲劳和皮疹。大多数患者最终都能康复，但关节痛通常可持续数月甚至数年。

疾病预防控制中心报告说(ID:chinameditour)，非洲，亚洲，欧洲以及印度洋和太平洋地区已经发生了疾病暴发。2013年底，基孔肯雅病毒首次在美洲的加勒比海岛屿上被发现，此后在美国得到报道，目前尚无疫苗或治疗方法。

严重发热伴血小板减少综合征

世卫组织也将其定义为“严重级”的血小板减少综合征（SFTS，也称为血小板减少症），是在中国，日本和韩国发现的一种新兴疾病。据最新报道，这种病毒似乎是通过蜱虫传播的。

主要症状是发高烧，以及血小板下降导致组织出血，淤青和缓慢的血液凝固。根据CDC的最新研究，韩国SFTS的死亡率为47.2％。

当前没有可用的治疗方法或疫苗。

寨卡病毒

这种一度隐晦的病毒最近造成了严重破坏，特别是在美洲。世卫组织宣布寨卡病为全球性公共卫生紧急事件，特别是新发现与出生缺陷和其他潜在的严重健康问题有联系后。

寨卡病毒是由埃及伊蚊和埃及白纹伊蚊等传播的。根据疾病预防控制中心的数据，尽管只有1/5的感染寨卡病毒的人会生病，但该病毒与小头畸形有关，小头畸形是一种先天不足，其头部偏小，大脑发育不全。 

（本文来源：医疗旅游微信公众号，原文作者：chinameditour）

参考资料

Going viral

You've heard of Ebola and likely Zika, but there are many dangerous viruses that have yet to make horrific headlines. A panel of scientists and public health experts gathered by the World Health Organization (WHO) met to discuss the top emerging pathogens most likely to cause severe outbreaks in the near future. These are viruses for which there is no vaccine and few, if any, treatments.

Here's a look at these diseases and what makes them so frightening.

Crimean-Congo hemorrhagic fever

Spread primarily to people from ticks and livestock, the Crimean-Congo hemorrhagic fever first emerged in Crimea in 1944, where it got the name Crimean hemorrhagic fever, according to the Centers for Disease Control and Prevention(CDC). Later, when it was recognized in 1969 as the culprit for illness in the Congo, the name changed to reflect the resulting illness. CCHF outbreaks have a fatality rate of as high as 40%,according to the WHO, and there is no vaccine.

Symptoms come on suddenly and include headache, high fever, vomiting, and back, joint and stomach pain. As the illness continues, there can be severe bruising and nosebleeds, as well as bleeding in the face, mouth and throat.

In some cases, the virus can be transmitted between people due to close contact with infected blood or bodily fluids. CCHF is found in many places including Africa, central Asia, the Middle East, eastern and southern Europe and India.

Ebola virus disease

The first known cases of Ebola, also known as Ebola hemorrhagic fever, were in 1976. Although early outbreaks occurred in remote villages in Central Africa near tropical rain forests, reports the WHO, more recent outbreaks were in urban areas as well. This severe illness results from a virus that is transmitted to people from wild animals then spread from humans to humans. The average fatality rate is 50% but has been as high as 90% in some outbreaks.

There are no Ebola vaccines but there are clinical trials under evaluation. Symptoms range from fever and vomiting to bleeding and weakness. Recovery depends on good supportive care and the patient's immune system.

Marburg hemorrhagic fever

Two mysterious outbreaks that occurred in Europe in the '60s were traced back to laboratory workers who handled African monkeys that had been imported from Uganda. A filovirus from the Ebola family of viruses, the virus is named after Marburg, the city in Germany where it was first detected. The natural host for the virus is believed to be fruit bats of the Pteropodidae family. The virus is transmitted from the bats to people and then spread through human-to-human contact.

Symptoms, which include high fever, severe headache and muscle aches, begin abruptly and quickly progress to include gastrointestinal issues, extreme lethargy and bleeding. In fatal cases — which up to 88% of instances are — death occurs in less than 10 days after symptoms start. There is no vaccine or treatment available.

The WHO has reported outbreaks in Angola, Democratic Republic of the Congo, Kenya, South Africa and Uganda.

Lassa fever

About 80% of people who become infected with the Lassa virus never have symptoms, reports the WHO. That's what makes it so difficult to detect the virus. The virus is a zoonotic illness that is transmitted to people via contact with food or household items contaminated with rat urine or feces. But it can also be spread from person to person via infected blood or fluids.

For those who have symptoms, they are usually mild and include a low fever and overall weakness. Those who have more serious symptoms may experience bleeding in their eyes, gums and nose, as well as vomiting, respiratory distress, facial swelling, deafness and severe pain. Only about 1% of Lassa virus infections result in death.

MERS and SARS coronavirus diseases

Middle East respiratory syndrome (MERS) and severe acute respiratory syndrome (SARS) are part of the coronavirus family — viruses that usually cause upper respiratory illnesses. Though virus transmission seems to come from infected camels, reports Smithsonian, both illnesses are easily spread through human sneezes and coughs.

SARS was first reported in Asia in 2003, according to the CDC, but the global outbreak was quickly contained and no more cases have been reported since 2004. MERS, however, was first reported in 2012 and has since spread to other countries. About 36% of patients who have reported MERS (shown here) have died, according to the WHO. There's no vaccine or treatment currently available.

Nipah and Rift Valley fever

The WHO recently named both these zoonotic diseases as some of the most dangerous emerging pathogens likely to cause severe outbreaks with a fatality rate as high as 75%. Nipah virus infection was first identified in 1998 when pig farmers in Malaysia became ill. More than one million pigs were euthanized as a response. In later outbreaks in India and Bagladesh, there were no obvious hosts. In 2018, the virus reappeared in India and killed 17. The virus was traced back to infected fruit bats (a natural host for the virus) in a well and rabbits being bred, reports CNN. Symptoms include respiratory issues and mental confusion.

Rift Valley fever was first identified in 1931 in sheep farmers in Kenya and has since been found in outbreaks mostly throughout Africa. The disease is transmitted by handling infected animal tissue, drinking infected milk or through the bites of infected mosquitoes. There has been no documented case of human-to-human transmission. Symptoms include fever, muscle pain and headache. A small percentage of patients get ocular disease or brain inflammation.

Neither Nipah virus infection or Rift Valley fever have vaccines.

Chikungunya

Chikungunya (pronounced chick-un-goon-ya) virus is spread to people by Aedes aegypti and Ae. albopictus (commonly known as the Asian tiger mosquito), the same insects that introduced us to dengue fever. Identified by the WHO as "serious," it causes fever and severe, sometimes debilitating joint pain. Other symptoms include muscle pain, headache, nausea, fatigue and rash. Most patients eventually recover, but often joint pain can persist for months and even years.

Disease outbreaks have occurred in Africa, Asia, Europe, and the Indian and Pacific Oceans, reports the CDC. In late 2013, the chikungunya virus was found for the first time in the Americas on islands in the Caribbean and has since been reported in the U.S. There is no vaccine or treatment. 

Severe fever with thrombocytopenia syndrome

Also identified by the WHO as "serious," severe fever with thrombocytopenia syndrome (also known as thrombocytopenia) is an emerging disease found in China, Japan and South Korea. The virus appears to be spread by ticks, reports UpToDate.

The main symptom is a very high fever, as well as a drop in blood platelets that causes tissue bleeding, bruising and slow blood clotting. According to a recent CDC study, the fatality rate for SFTS in South Korea was 47.2%. Currently there is no treatment or vaccine available.

Zika

This once-obscure virus has been wreaking havoc recently, especially in the Americas. The WHO declared Zika a global public health emergency, especially because of newfound links with birth defects and other potentially severe health problems.

Zika is transmitted by infected Aedes mosquitoes like Aedes aegypti and Aedes albopictus, also known as the Asian tiger mosquito. Although only about one in five people infected with Zika virus will get sick, according to the CDC, the virus is linked to microcephaly, a birth defect characterized by an undersized head and incomplete brain development.