Scientists say coronaviruses related to Sars-CoV-2 may be circulating in bats across many parts of Asia.
A virus that is a close match to the Sars-CoV-2 virus, which causes Covid-19, has been discovered in bats at a wildlife sanctuary in eastern Thailand.
The researchers predict that related coronaviruses may be present in bats across many Asian nations and regions.
Their discovery extends the area in which related viruses have been found to a distance of 4,800km (2,983 miles).
The study is reported in Nature Communications.
Writing in the journal, the researchers said the sampling site (Thailand only) and sampling size was limited, but they were confident that coronaviruses "with a high degree of genetic relatedness to Sars-CoV-2 are widely present in bats across many nations and regions in Asia".
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TASS/. The international group of scientists has discovered traces of the SARS-CoV-2 strain in bats dwelling outside China. Thus, according to director of the program in emerging infectious diseases of the National University of Singapore Linfa Wang, it is possible to say that the virus was imported to China’s Wuhan from somewhere else. "It’s almost impossible to imagine this virus came from Wuhan," he stated earlier.
ReplyDeleteAccording to research published on Tuesday as co-authored by the Singaporean scientist, a 96.2%-similar strain was also discovered in bats in China’s Yunnan and a strain with a 91.2% overlap was found in bats in Thailand.
The researchers used serological tests in order to detect the presence of antibodies similar to SARS-CoV-2 in bats and pangolins. This method is used to establish the presence of the virus in the past yet does not detect it in the present. As a result, four out of 98 species displayed a high level of antibodies, the study points out. At the same time the experts could not fully study the pangolins due to their protected status in Thailand.
The scientists also noted that horseshoe bats (Rhinolophus hipposideros) inhabit not only Asia but also Australia and Europe.
Les experts de l'OMS en visite à Wuhan ont jugé mardi comme "la plus probable" la piste d'une transmission du coronavirus par un animal intermédiaire, au terme de leur mission dans cette ville de Chine frappée en premier par l'épidémie.
DeletePlus d'un an après la découverte des premiers cas de contamination dans cette métropole de 11 millions d'habitants, ils ont balayé l'hypothèse d'une fuite d'un laboratoire, sans écarter celle d'une transmission par les produits surgelés -- privilégiée par Pékin.
La théorie la plus probable pour expliquer l'origine de l'épidémie reste celle de la contamination de l'être humain par un animal "intermédiaire", a déclaré le chef de la mission de l'Organisation mondiale de la santé (OMS), Peter Ben Embarek, lors d'une conférence de presse.
Cet animal n'a toutefois "pas encore été identifié", a indiqué Liang Wannian, le chef de l'équipe de scientifiques chinois.
L'hypothèse de la fuite d'un laboratoire, soulevée par l'administration de l'ancien président américain Donald Trump, est en revanche "hautement improbable", a déclaré Peter Ben Embarek.
Washington avait accusé l'Institut de virologie de Wuhan, qui mène des recherches sur des pathogènes très dangereux, d'avoir laissé s'échapper le coronavirus, volontairement ou non.
Prenant le contre-pied de commentaires initiaux de l'OMS, M. Ben Embarek a également évoqué "la possibilité" d'une transmission du coronavirus "via le commerce des produits surgelés".
"Il serait intéressant d'examiner si un animal sauvage congelé qui a été infecté a pu être un vecteur potentiel", s'est-il interrogé.
Bats and pangolins are certainly not the animal reservoir of the COVID-19, since the coronaviruses identified in these species are not sufficiently similar to SARS-CoV-2, Liang Wannian, a Chinese expert from Tsinghua University, said on Tuesday.
ReplyDelete"Coronaviruses most highly related to SARS-CoV-2 are to be found in bats and pangolins, suggesting they could be the reservoir of the virus that causes COVID-19, on the basis of high similarity and sequences between the standard viruses and SARS-CoV-2. However, the viruses identified so far from neither of these species are sufficiently similar to SARS-CoV-2 to serve as direct progenitor of the SARS-CoV-2," Liang said at a press conference of the World Health Organization's expert team.