A coronavirus closely related to the human Severe Acute Respiratory Syndrome (SARS) virus has been found in some wild bats in Hong Kong, China, scientists said in a study released on Saturday.
In a paper to be published in next week's US journal Proceedings of National Academy of Sciences, the researchers from Hong Kong University warned that wild animals with this virus, a genetic relative to the human SARS virus, should be handled with precaution.
Although the finding of SARS coronavirus in caged palm civets from live animal markets in China has provided evidence for interspecies transmission in the genesis of the SARS epidemic in 2002-03, the civet may have served only as an amplification host that transfers SARS coronavirus from wild reservoirs to humans, said the researchers.
To investigate further, a team led by Professor Kwok-yung Yuen launched a surveillance study for coronavirus in noncaged animals from the wild areas of the Hong Kong Special Administrative Region(HKSAR), China. The researchers believed the wild animals may have closely contacted with civets.
They identified this new coronavirus from 23 of 59 anal swabs of wild Chinese horseshoe bats (Rhinolophus sinicus), and named it bat-SARS-Coronavirus. Sequencing and analysis of three bat-SARS-Coronavirus genomes from samples collected at different dates showed this virus is closely related to SARS coronavirus from humans and civets, the researchers said.
In addition, genetic data also suggests that the bat-SARS-Coronavirus has a common ancestor with civet SARS coronavirus. But the researchers could not yet determine how the bats were originally infected, or whether this species was responsible for transmitting the SARS coronavirus to other mammals including the civets.
Bats, the only flying mammals, are an important reservoir of emerging zoonotic viruses, including rabies virus, lyssa virus, Hendra and Nipah viruses.
Wild bats carrying this coronavirus, which can be detected only in anal swabs without causing any symptom of disease, may become potential threats to humans, they noted.
"In this study, three different coronaviruses were identified from wild bats in the HKSAR, suggesting that these animals are an important reservoir for coronavirus. Continuous surveillance for coronavirus in these flying mammals with roosting behavior is indicated to assess their potential threats to human health," the paper said.