VOA慢速英语--废水检测可以确定医院和学校的疫情情况

Wastewater Testing Could Identify Outbreaks at Hospitals, Schools

Researchers have launched several projects to test coronavirus levels at hospitals and schools to identify new outbreaks.

The new projects are using similar sewage testing methods that some cities and countries around the world have already used. Earlier efforts centered on wastewater tests in order to follow the progression of the coronavirus over large population areas. But the new programs aim to test sewage from single buildings, such as hospitals, schools and care centers.

The coronavirus is mainly spread through small drops coming from an infected person's mouth and nose. But studies have shown that it can also be released through human waste.

The researchers say testing wastewater can help identify where the virus is spreading and reduce the need for mass testing. The collection and examination of sewage from buildings costs much less than testing hundreds of individual people.

Wastewater tests can also be carried out often and quickly. With infection rates rising again in much of the world, it is especially important for schools, hospitals and care centers to be able to catch new cases early.

Francis Hassard is an expert in public health microbiology with Britain's Cranfield University. "What we're trying to do is identify outbreaks before they happen," he told the Reuters news agency.

Hassard is helping¹ lead a project that started collecting samples at 20 secondary schools in London last month. The team, which is financed by the British government, plans to expand its sampling to at least 70 schools. The effort is currently still a research project aimed at testing the system's methods.

In Canada, researchers at the University of Calgary have been gathering² samples from three local hospitals, including one that experienced a recent outbreak that killed 12 people. The team was still working to improve its methods when the outbreak happened.

When researchers went back to test wastewater, they found the amount of coronavirus genetic³ material had jumped 580 percent as the virus spread, said Kevin Frankowski. He is director of the university's Advancing Canadian Wastewater Assets project.

"We saw a very significant change," Frankowski said. "It was really strong proof that this ... (method) works."

The project shares data with Alberta Health Services, which runs a large number of hospitals. Frankowski said that if levels show a sharp rise again, hospital officials could immediately start testing individuals or take other steps to limit the spread.

In the United States, the professional services company GHD has set up wastewater testing at several university housing buildings. It also started advertising⁴ the service to long-term care homes. The service has already received interest, GHD's Peter Capponi told Reuters.

So far, most of the world's wastewater testing for coronavirus has been completed at sewage treatment plants. But it can take 24 to 36 hours for waste to arrive at a treatment plant. And heavy rain or industrial runoff can dilute⁵ samples.

When virus levels rise at a treatment plant, it is not always clear what actions officials should take. But when virus material suddenly appears in sewage leaving a single building, the next steps are more clear.

At the University of Arizona, for example, sewage from one student tested positive for coronavirus on August 25. The next day, the university began testing students. Two tested positive and were immediately isolated⁷, the school said. University officials said the early action may have prevented a severe outbreak.

Words in This Story

outbreak – n. a sudden start or increase of fighting or disease

sewage – n. wastewater and human waste products

sample – n. a small amount of something that represents what it is like

significant – adj. important or noticeable

dilute – v. to make a liquid thinner or weaker by adding water or another liquid to it

positive – adj. in a medical test, positive means the person being tested has a disease or condition

isolate⁶ – v. to put or keep (someone or something) in a place or situation that is separate from others

1 helping   

n.食物的一份&adj.帮助人的，辅助的

参考例句：

• The poor children regularly pony up for a second helping of my hamburger. 那些可怜的孩子们总是要求我把我的汉堡包再给他们一份。
• By doing this, they may at times be helping to restore competition. 这样一来, 他在某些时候,有助于竞争的加强。

2 gathering   

n.集会，聚会，聚集

参考例句：

• He called on Mr. White to speak at the gathering.他请怀特先生在集会上讲话。
• He is on the wing gathering material for his novels.他正忙于为他的小说收集资料。

3 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

4 advertising   

n.广告业；广告活动 a.广告的；广告业务的

参考例句：

• Can you give me any advice on getting into advertising? 你能指点我如何涉足广告业吗?
• The advertising campaign is aimed primarily at young people. 这个广告宣传运动主要是针对年轻人的。

5 dilute   

vt.稀释，冲淡；adj.稀释的，冲淡的

参考例句：

• The water will dilute the wine.水能使酒变淡。
• Zinc displaces the hydrogen of dilute acids.锌置换了稀酸中的氢。

6 isolate   

vt.使孤立，隔离

参考例句：

• Do not isolate yourself from others.不要把自己孤立起来。
• We should never isolate ourselves from the masses.我们永远不能脱离群众。

7 isolated   

adj.与世隔绝的

参考例句：

• His bad behaviour was just an isolated incident. 他的不良行为只是个别事件。
• Patients with the disease should be isolated. 这种病的患者应予以隔离。