VOA慢速英语2020 报告显示许多冠状病毒感染者没有任何症状（在线收听）

报告显示许多冠状病毒感染者没有任何症状

New research suggests that many people have had the coronavirus without any symptoms of it. If confirmed, experts hope that the virus will be much less deadly than they feared.

新研究表明，许多冠状病毒感染者没有任何症状。如果得到证实，专家希望该病毒的致命性能远远低于他们所担心的情况。

It also means, however, that it is impossible to know who may be contagious. That would complicate decisions on when return to work or to school.

然而，这也意味着，无法知道谁可能具有传染性。这将令何时复工或返校的决策过程复杂化。

Over the past week, reports of infections without symptoms have come from a homeless shelter in Massachusetts and pregnant women at a New York hospital. Other "silent" infections were reported in California, several European countries and even on a United States Navy aircraft carrier.

过去一周，马萨诸塞州一家无家可归人员收容中心和纽约一家医院报告了无症状感染者，医院中的无症状感染者为孕妇。此外，加州、欧洲多国、甚至一艘美国海军航空母舰也报告了“沉默的”感染者。

The head of the U.S. Centers for Disease Control and Prevention says 25 percent of infected people might not have symptoms of the virus. The vice chairman of the Joint Chiefs of Staff, General John Hyten, thinks the rate may be as high as 60 to 70 percent among armed forces members.

美国疾病预防控制中心主任表示，25%的新冠病毒感染者可能没有症状。美国参谋长联席会议副主席约翰·海顿认为，武装部队人员中可能有多达60%至70%的病例为无症状感染者。

None of these numbers can be fully trusted because they are based on incomplete testing, said Michael Mina. He is a doctor with the Harvard University School of Public Health. He added that the numbers suggest "we have just been off...by huge, huge numbers" for estimating total infections.

迈克尔·米纳说，这些数字并非完全可信，因为它们基于的是不完整的检测。米纳是哈佛大学公共卫生学院的医生。他补充说，这些数字表明，估算受感染的总人数时，“我们可能漏掉了很大一批人”。

Worldwide, tests have confirmed more than 2.3 million coronavirus infections and more than 160,000 deaths. The virus has caused large economic and social harm since its existence was reported in early January.

在全球范围内，经检测确诊了超过230万例冠状病毒病例，其中死亡病例超过16万例。自1月初该病毒的存在被报告以来，其已造成了巨大的经济和社会危害。

No-Symptom Cases

无症状病例

Based on known cases, health officials have said the virus usually causes mild or moderate health problems similar to influenza. They include feeling tired and a higher than normal body temperature. Patients may also report having a dry cough.

卫生官员表示，根据已知病例情况，该病毒通常会引发类似于流感的轻微或中度健康问题。症状包括感觉疲倦和高于正常的体温。患者可能还会出现干咳。

Now evidence is growing that a great number of people may have no symptoms at all.

越来越多的证据表明，很多人可能根本没有任何症状。

Scientists in Iceland tested six percent of the country's population to see how many were infected without showing any symptoms. They found that about 0.7 percent tested positive for the virus. So did 13 percent of a group at higher risk because of recent travel or being in contact with someone sick.

冰岛科学家对该国6%的人口进行了检测，以了解有多少感染者没有任何症状。他们发现，约0.7%的人在冠状病毒检测中呈阳性。近期曾旅行或曾接触病例的感染“高风险”人群中，13%检测结果呈阳性。

On the aircraft carrier USS Theodore Roosevelt, one crew member died from the virus. Vice Admiral Phillip Sawyer, deputy commander of naval operations, reported that 40 percent of the crew members are symptomatic. The percentage may increase if more develop symptoms later, he warned.

美国“西奥多·罗斯福”号航空母舰上一名船员死于该病毒。美国海军作战部副司令划利普·索耶中将报告说，40%的船员出现感染症状。他警告说，如果之后出现更多症状，那这一比例可能会增加。

In New York, a hospital tested pregnant women coming in to give birth over a two-week period. Nearly 14 percent of those woman had the coronavirus, but no symptoms. Some developed symptoms later.

纽约一家医院对两周内所有入院分娩的孕妇进行了病毒检测。近14%的孕妇没有任何相关症状，却携带病毒。部分孕妇在检测后出现症状。

Nearly 50 percent of the people on the Diamond Princess cruise ship had coronavirus, but no symptoms. Researchers now estimate that 18 percent of those infected never developed symptoms.

在“钻石公主”号邮轮上，近一半人感染了冠状病毒，但没有症状。研究人员估计，这些感染者中大约有18%从未出现症状。

Problems with methods

所用方法存在问题

All these studies used tests that are problematic. Some involved throat and nose swabs that can miss the virus.

所有这些研究所使用的检测方法均存在瑕疵。有些检测使用咽拭子或鼻拭子，这可能会造成病例遗漏。

Symptoms may not appear when someone is tested but turn up later. One Japanese study found that more than 50 percent of those who had no symptoms when they tested positive later felt sick.

症状可能不会在人们接受检测时出现，但会在随后显现。一项日本研究发现，在检测中呈阳性的人中，超过50%没有任何症状，但之后会感觉不适。

Better answers may come from newer exams that test blood for antibodies.The body's natural defenses against disease produce antibodies to fight the virus. But it is still unclear if these tests can be trusted.

更好的解决方法可能需要进行较新的检查，即检测血液中的病毒抗体。人体抵抗疾病的自然防御机制产生抗体来对抗该病毒。但目前尚不清楚这些检测是否可信。

On Friday, researchers reported results from antibody tests on 3,300 people in Santa Clara county, California. They said that between 1.5 percent and 2.8 percent have been infected. That would mean 48,000 to 81,000 cases in the county, which is more than 50 times the number that have been confirmed.

上周五，研究人员报告了加州圣克拉拉县3300人的抗体检测结果。他们表示，感染率为1.5%至2.8%。这意味着，该县有4.8万至8.1万例病例，比已公布确诊病例数高出50倍。

These studies have yet to be published, and some scientists question the information. Those tested answered social media advertisements, which means they may have believed they already had the virus and wanted a test.

这些研究尚未发表，一些科学家对这些信息表示质疑。接受检测者由社交媒体广告招募，这意味着他们可能认为自已已经感染了病毒，并希望进行检测。

Next Steps

下一步措施

Antibody testing needs to be done in a methodical way, Mina said.

米纳表示，抗体检测需要以有条不紊的方式进行。

The CDC and other groups are planning such studies. They could help with the process of returning to normal life.

美国疾控中心和其他组织正在规划这类研究。这些研究可以帮助恢复正常生活。

If the virus is widespread and there are many people without symptoms, it is possible that some have developed a level of immunity. That could stop the spread. But scientists warn that a lot more research is needed.

如果该病毒广泛传播，而许多人没有症状，那可能有些人已经有了一定程度的免疫。这可以阻止传播。但科学家警告称，需要进行更多研究。

I'm Jonathan Evans.

乔纳森·埃文斯报道。

Words in This Story

symptom – n. an indicator that one is sick

contagious – adj. an illness that can be passed from one person to another

complicate – v. making more difficult or complex

positive – adj. an outcome that indicates an affirmative

swab – n. a small piece of cotton or clothe

cough – n. sudden expiration from the throat