Section outline

  • A man with a sad expression, holding a handkerchief, showing signs of illness.

    Viral or bacterial?
    ::病毒还是细菌?

    Doesn't look like fun. The flu is caused by an influenza . And usually a slightly different virus every season.
    ::流感是由流感引起的, 通常每个季节都有一种略有不同的病毒。

    Viruses and Human Disease
    ::病毒和人类疾病

    Viruses cause many human diseases. In addition to the flu and , viruses cause rabies, measles, diarrheal diseases, hepatitis, polio, cold sores and other diseases (see Figure  ). Viral diseases range from mild to fatal. One way viruses cause disease is by causing host to burst open and die. Viruses may also cause disease without killing host cells. They may cause illness by disrupting in host cells.
    ::除了流感和病毒导致狂犬病、麻疹、腹泻、肝炎、脊髓灰质炎、寒痛和其他疾病(见图)外,病毒还造成许多人类疾病。病毒造成疾病的方式之一是造成宿主爆发和死亡。病毒也可能造成疾病,而不导致宿主细胞死亡。病毒可能扰乱宿主细胞,造成疾病。

    Image showing a person's lips affected by cold sores caused by a herpes virus.
    Cold Sore. Cold sores are caused by a herpes virus.

    Some viruses live in a dormant state inside the body. This is called latency . For example, the virus that causes chicken pox may infect a young child and cause the short-term disease chicken pox. Then the virus may remain latent in nerve cells within the body for decades. The virus may re-emerge later in life as the disease called shingles. In shingles, the virus causes painful skin rashes with blisters (see Figure  ).
    ::某些病毒存在于体内的休眠状态中, 这被称为静脉。 比如, 导致天花的病毒可能会感染幼小儿, 并引发短期的疾病。 然后病毒可能会在体内的神经细胞中潜伏数十年。 病毒可能会在生命的后期再次出现, 以这种疾病命名为闪烁。 在闪烁中, 病毒会引发疼痛的皮疹和泡泡(见图 ) 。

    Skin rash showing blisters, indicating an outbreak of shingles on a person's torso.
    Shingles. Shingles is a disease caused by the same virus that causes chicken pox.

    Some viruses can cause . For example, human papillomavirus (HPV) causes cancer of the cervix in females. Hepatitis B virus causes cancer of the liver . A viral cancer is likely to develop only after a person has been infected with a virus for many years.
    ::例如,人类乳头瘤病毒(HPV)导致雌性宫颈癌,乙型肝炎病毒导致肝癌,病毒癌症只有在感染病毒多年后才可能发作。

    The Flu
    ::流感

    Influenza, or flu, is a contagious respiratory illness caused by influenza viruses. Influenza spreads around the world in seasonal epidemics . An epidemic is an outbreak of a disease within a of people during a specific time. Every year in the United States, about 200,000 people are hospitalized and 36,000 people die from the flu. Flu pandemics can kill millions of people. A pandemic is an epidemic that spreads through human populations across a large region (for example a continent), or even worldwide. Three influenza pandemics occurred in the 20th century and killed tens of millions of people, with each of these pandemics being caused by the appearance of a new strain of the virus. Most influenza strains can be inactivated easily by disinfectants and detergents.
    ::流感或流感是流感病毒引起的传染性呼吸道疾病; 流感在季节性流行病中蔓延到世界各地; 流行病是在特定时间内在某一人群中爆发的一种疾病; 美国每年约有200 000人住院,36 000人死于流感; 流感可以杀死数以百万计的人; 流感是一种流行病,在广大地区(例如一个大陆),甚至在全世界蔓延; 三种流感流行病发生在20世纪,使数以千万计的人丧生,每一种流行病都是由病毒新菌株的出现造成的; 多数流感菌株很容易因消毒剂和洗涤剂而失去活动能力。

     

     

    Emerging Viral Diseases
    ::新出现的病毒性疾病

    Modern modes of transportation allow more people and products to travel around the world at a faster pace. They also open the airways to the transcontinental movement of infectious disease vectors . One example of this occurring is West Nile Virus , which scientists believe was introduced to the United States by an infected air traveler. With the use of air travel, people are able to go to foreign lands, contract a disease and not have any symptoms of illness until they get home, possibly exposing others to the disease along the way. 
    ::现代交通方式可以让更多的人和产品以更快的速度在世界各地旅行,它们也打开通向传染病病媒跨洲移动的空气通道,其中一个例子就是西尼罗河病毒,科学家们认为,该病毒是一名受感染的航空旅行者向美国引进的。 利用空中旅行,人们可以前往外国领土,感染一种疾病,在回家之前不会有任何疾病症状,并可能让其他人在路上染上这种疾病。

    Often, new diseases result from the spread of an existing disease from to humans. A disease that can be spread from animals to humans is called a zoonosis . When a disease breaks out, scientists called epidemiologists investigate the outbreak, looking for its cause. Epidemiologists are like detectives trying to solve a crime. The information epidemiologists learn is important to understand the , and help prevent future outbreaks of disease.
    ::通常,新的疾病是由现有疾病从人类传播到人类。 一种疾病可以从动物传播到人类,称为“动物传染病 ” 。 当疾病爆发时,科学家称之为流行病学家,调查疫情,寻找原因。 流行病学家就像侦探一样试图解决犯罪。 信息流行病学家学会了理解信息的重要性,帮助预防未来疾病爆发。

    A deadly strain of avian flu virus named H5N1 has posed the greatest risk for a new influenza pandemic since it first killed humans in Asia in the 1990s. The virus is passed from infected to humans. Fortunately, the virus has not mutated to a form that spreads easily between people.
    ::一种名为H5N1的致命禽流感病毒菌株自1990年代首次在亚洲杀死人类以来,对新的流感大流行构成了最大的风险。 病毒从感染者传染给人类。 幸运的是,病毒并没有变异为一种容易在人与人之间传播的形式。

    Several lethal viruses that cause viral hemorrhagic fever have been discovered, two of which are shown in the Figure  . Ebola outbreaks have been limited mainly to remote areas of the world. However, they have gained extensive media attention because of the high mortality rate—23 percent to 90 percent—depending on the strain. The primary hosts of the viruses are thought to be apes in west central Africa, but the virus has also been isolated from bats in the same region.
    ::已经发现了几种导致病毒性出血热的致命病毒,其中两个在图中显示。 埃博拉疫情的爆发主要局限于世界偏远地区,但是,由于高死亡率(23%至90%)取决于这一菌株,这些病毒得到了媒体的广泛关注。 据认为,这些病毒的主要宿主是非洲西部的猿类,但病毒也与同一地区的蝙蝠隔离开来。

    Images of Ebola virus (left) and Marburg virus (right) under a microscope.
    The Ebola virus (left), and Marburg virus (right), are viruses that cause hemorrhagic fevers that can cause multiple organ failure and death.

    Ebola is a rare and deadly disease caused by infection with a strain of Ebola virus. The 2014 Ebola epidemic affected multiple countries in West Africa, including Guinea, Sierra Leone and Liberia. Ebola is spread through direct contact with and body fluids of a person infected by and already showing symptoms of Ebola. Ebola is not spread through the air, , food , or mosquitoes.
    ::埃博拉是一种罕见和致命的疾病,是埃博拉病毒感染造成的。 2014年埃博拉疫情影响到包括几内亚、塞拉利昂和利比里亚在内的西非多个国家。 埃博拉通过直接接触受埃博拉感染并已经表现出埃博拉症状的人,并通过其体液传播。 埃博拉不会通过空气、食物或蚊子传播。

    People get exposed to new and rare zoonoses when they move into new areas and encounter wild animals. For example, severe acute respiratory syndrome ( SARS ) is a respiratory disease which is caused by the SARS coronavirus. An outbreak in China in 2003 was linked to the handling and consumption of wild civet cats sold as food in a market. In 2005, two studies identified a number of SARS-like coronaviruses in Chinese bats. It is likely that the virus spread from bats to civets, and then to humans.
    ::例如,严重急性呼吸系统综合征(SARS)是一种呼吸道疾病,是由SARS冠状病毒引起的。2003年中国爆发的这种疾病与处理和消费在市场上作为食品出售的野生小猫有关。2005年,两项研究发现中国蝙蝠中存在一些类似于SARS的科罗纳病毒。病毒很可能从蝙蝠传播到食肉动物,然后传播到人类。

    A novel type of coronavirus was discovered in 2019, first in China and then globally. The novel virus is named Severe Acute Respiratory Syndrome Coronavirus 2  (SARS-CoV-2). The disease itself is referred to as coronavirus disease 2019 (COVID-19).
    ::2019年发现了一种新型的冠状病毒,先是在中国,然后是全球。新病毒被称为严重急性呼吸系统综合症科罗纳病毒2 (萨斯-科沃-2),它本身被称为冠状病毒病2019 (COVID-19 ) 。

     

     

    Summary
    ::摘要

    • Viruses cause many human diseases by killing host cells or disturbing their homeostasis.
      ::病毒通过杀死宿主细胞或扰乱其主细胞的顺势造成许多人类疾病。
    • Viruses are not affected by antibiotics. Several viral diseases can be treated with antiviral drugs or prevented with vaccines.
      ::病毒不受抗生素影响,几种病毒性疾病可以用抗病毒药物治疗,也可以用疫苗预防。
    • Several emerging viral diseases exist: West Nile Virus, Ebola, SARS, and COVID-19.
      ::存在几种新出现的病毒性疾病:西尼罗病毒、埃博拉、萨斯和COVID-19。

    Explore More 
    ::探索更多

    Explore More I
    ::探索更多

    Use the resource below to answer the questions that follow.
    ::利用以下资源回答以下问题。

    • Which is better: Soap or hand sanitizer?:
      ::更好的是:肥皂还是洗手液?

     

     

    1. What is the outer surface of the coronavirus that causes COVID-19 made of?
      ::导致COVID-19的冠状病毒的外表是什么?
    2. What are amphiphiles? Which biological molecules do they resemble?
      ::什么是两栖生物?它们像什么生物分子?
    3. Distinguish between how hand sanitizer versus soap and water disrupt the outer membrane of the coronavirus that causes COVID-19.
      ::区分人工净化剂与肥皂和水如何破坏导致COVID-19的冠状病毒的外膜。
    4. Is hand sanitizer or soap and water better to use to prevent  the spread of COVID-19?
      ::洗手剂或肥皂和水是否更好地用于防止COVID-19的扩散?
    5. What are the benefits to using soap and water to prevent  the spread of COVID-19?
      ::使用肥皂和水防止COVID-19扩散有什么好处?

    Explore More II
    ::探索更多情况二

    Use the resource below to answer the questions that follow.
    ::利用以下资源回答以下问题。

    • U.S. Mortality: Death Certificates Listing Pneumonia, Influenza, and COVID-19: 
      • Animated GIF: 
        ::动画 GIF :
      • Static Image:   
        ::静态图像 :

      ::美国死亡率: 肺炎死亡证书清单、流感和COVID-19:动画GIF:静态图象:
    1. The peak percent of deaths is observed as a result of what disease(s)?
      ::死亡的高峰是何种疾病造成的?
    2. What might you infer about the disease(s) that are causing the percent of deaths at this peak?
      ::造成这个峰值死亡百分比的疾病?
    3. The graph indicates a peak in the percent of deaths ending the week of April 11, 2020. During this time in the US (March 2020 - May 2020), widespread stay-at-home policies were put into place with strict social distancing guidelines. According to the data provided, how do you think these measures impacted the percent of deaths during this time?
      ::图表显示了到2020年4月11日这一周为止的死亡人数比例的峰值。 在此期间,在美国(2020年3月至2020年5月),根据严格的社会偏移准则实施了广泛的家庭停留政策。 根据所提供的数据,你认为这些措施对这段时期死亡人数的百分比有何影响?

    Review
    ::回顾

    1. How do viruses cause human disease?
      ::病毒如何导致人类疾病?
    2. What is an epidemic? Why can the flu be considered an epidemic?
      ::什么是流行病?为什么流感可以被视为流行病?
    3. What is latency? Give an example of a virus that undergoes this process.
      ::潜伏是什么? 举个例子来说明这个过程所经历的病毒。