首页
登录
职称英语
Wild ducks and other migratory (迁移的) birds could be important carriers of dea
Wild ducks and other migratory (迁移的) birds could be important carriers of dea
游客
2024-06-04
2
管理
问题
Wild ducks and other migratory (迁移的) birds could be important carriers of deadly bird flu, researchers say. Even so. the infectious-disease experts say there is no solid basis for killing wild birds to protect poultry and minimize the risk. of human infection.
The European team investigating the global spread of the It5N1 strain of avian influenza (禽流感) says certain duck species may be infecting wild bird populations. Geese and wading birds are also possible vectors (带菌者) of the virus, the team says.
The team’s study was led by Bjorn Olsen of Umea University in Sweden~ Olsen runs Europe’s largest wild-bird flu monitoring program.
Studies have shown that influenza viruses in lake water, generally passed via bird feces(粪), can stay infectious for up to 30 days. The migration or feeding behavior of dabbling ducks could at least partially explain the spread of the H5NI strain of bird flu, the researchers add.
This group of duck species Includes mallards, teal, pintails, and others that feed at or near the surface, where viruses in water are most likely to be picked up. Perhaps as a result, dabblers have the highest known rates of avian influenza infection, the study says. For instance, nearly 13 percent of mallards tested positive for bird flu. Other species tested include the American black duck (18.1 percent) blue-winged teat (11.5 percent) and northern pintail (11.2 percent).
However, bird flu viruses appear to exist in ducks in a low-pathogenic form, meaning infection doesn’t usually lead to severe illness and death.
"Dabbling ducks are for sure the prime hosts for low pathogenic viruses" said study co-author Ron Fouchier a virologist at the Erasmus Medical Center in Rotterdam, Netherlands. "But the big question is, how much of our knowledge about these viruses can we translate to high-pathogenic viruses such as the H5N1 strain of bird flu?"
In poultry avian viruses can mutate(变异) into more virulent influenza strains, including H5NI. If this mutated virus then finds its way back into wild populations, the birds could then spread the disease through migration.
Some scientists have argued that wild birds infected with HN51 would be too iii to migrate. Swans. for instance, appear to be particularly vulnerable to the strain. "Swans apparently drop dead quite easily, but they are unlikely to be the vector because they are not going to fly very far if they are dead," Fouchier said.
But the study team says that some birds that have been purposely infected for the sake of research show that wild birds can survive HSN1. "For some reason H5NI has adapted so it no longer kills dabbling ducks." Fouchier said. This means the ducks may be able to spread the virus over a wide area.
The study team says migratory geese may also be vectors, because they often graze in huge flocks, a practice that could encourage transmission.
Migrating ducks, the researchers add, "could provide an intercontinental bridge" for bird flu to North America. which has not yet had any known cases of HSNI. [br] According to the author, what may be the possible carriers of bird flu?
选项
答案
Wild ducks and other migratory birds./ Ducks, geese and wading birds.
解析
文章开头指出,野鸭以及其他迁徙鸟类可能是致命性禽流感的重要携带者,由此可得答案;第二段又提到,鸭子可能在传染野鸟,而鹅和涉水鸟也可能是病毒的携带者,由此也可得答案。
转载请注明原文地址:https://tihaiku.com/zcyy/3619176.html
相关试题推荐
TheMostImportantSecretAboutTrustWhatIsT
TheMostImportantSecretAboutTrustWhatIsT
TheMostImportantSecretAboutTrustWhatIsT
TheMostImportantSecretAboutTrustWhatIsT
Themostimportanttechnologicaleventofourtimeistheriseofthecomput
Themostimportanttechnologicaleventofourtimeistheriseofthecomput
Themostimportanttechnologicaleventofourtimeistheriseofthecomput
Themostimportanttechnologicaleventofourtimeistheriseofthecompu
Themostimportanttechnologicaleventofourtimeistheriseofthecompu
Themostimportanttechnologicaleventofourtimeistheriseofthecompu
随机试题
InDeathValley,California,oneofthehottest,mostaridplacesinNorthAm
[originaltext]M:Goodmorning,DrHealy.Welcometo"TheyearstoCome".W:Tha
Children’sHealthcareofAtlantawantstomoveGeorgiaoutofthetop10lis
以下建筑中()符合高层建筑的判定标准。A.建筑高度为27m的住宅建筑 B.建
截至2016年底,河北省具有国家级历史文化名城()座。A.3 B.4 C.
“君主之官,神明出焉”指的是A.肝 B.心 C.脾 D.肺 E.肾
下列各项中,对封闭式基金的认识不正确的是()。A:经核准的基金份额总额在基金合同
医院感染监测可分为()A.暴发流行监测和危险因素监测 B.发病率监测和漏
患者男,61岁。良性前列腺增生,无明显症状,无残余尿。目前最适宜的处理措施是A、
在我国,依法对期货公司的金融期货结算业务实行自律管理的机构是()。A.中国期
最新回复
(
0
)