As many countries emerge from lockdowns, researchers are prepared to use genome sequencing to avoid an expected second wave of C

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问题     As many countries emerge from lockdowns, researchers are prepared to use genome sequencing to avoid an expected second wave of COVID-19 infections. Since the first whole-genome sequence of the new coronavirus, SARS-CoV-2, was shared online on 11 January, scientists have sequenced and shared some 32,000 viral genomes from around the world. Such a vast amount of data has allowed researchers to trace the origin of COVID-19 outbreaks in their countries and pinpoint when community transmission occurred.
    Now, countries that have successfully suppressed infections are entering the next phase of the COVID-19 pandemic—where there’s a risk of new cases appearing as social restrictions ease. Researchers say that genomics will be crucial to quickly track and control these outbreaks. Studies already show that outbreaks tend to be shorter and smaller when genomics is used to help contact tracing. "When there are few cases, genomics can very quickly tell you what you’re dealing with and therefore guide precision interventions," says Gytis Dudas, a consulting bioinformatician at the Gothenburg Global Biodiversity Centre in Sweden.
    Several places are particularly well placed to do that because they invested in genome sequencing early in the pandemic and have a relatively small number of cases. Researchers in New Zealand, and at least one state in Australia decided that they would aim to sequence most coronavirus genomes in their country or state. As SARS-CoV-2 spread around the world, distinct lineages began to form as viruses circulating in different regions gradually evolved. By comparing sequences, researchers can quickly rule out possible lines of transmission if two sequences don’t match, or link together cases that do.
    Scientists in the United Kingdom, the United States and other countries are also sequencing SARS-CoV-2 from a large proportion of cases there, but because their epidemics are still ongoing and case numbers are high, genomics is being used to monitor spread and help identify the source of some cases where contact tracing fails. But such interventions depend on broad sampling, and so in places where diagnostic testing is limited, there will also be gaps in the genomic data.
    But the use of genomic analysis to help contact tracing is largely restricted to high-income countries, says Meru Sheel, an epidemiologist at the Australian National University in Canberra. She would like to see genomics considered as a tool for outbreak responses in resource-limited countries in the Asia-Pacific region, as it was in the Democratic Republic of the Congo, Sierra Leone and Guinea during the Ebola outbreak.
Which of the following would be the best title for the text?

选项 A、What can researchers do with genome sequence?
B、When will the second wave of pandemic come?
C、Why is genome sequence so important?
D、How are countries using genomics to help avoid a second wave of COVID-19?

答案D

解析 主旨题。本题考查文章最适合的标题,属于主旨题,考生要关注文章的整体大意和关键词,尤其要重点关注文章前两段。根据文章的首段内容可知,“研究人员准备利用基因组测序来避免预计到来的第二波新冠肺炎疫情感染。”同时文章多次提及基因组学的用途,如“研究人员表示. 基因组学对快速追踪和控制疫情爆发至关重要”“基因组学也正被用于监测传播,并在追踪失败的情况下帮助确认一些病例的接触源头”等。由此可以推测,各国都在通过基因组学来避免第二波新冠肺炎疫情,故D项正确。A项以偏概全,不够宏观概括,故排除。B项和C项都没有提及,属于无中生有,故也排除。
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