Mutated strain that caused outbreak appears to have European origins Experts said it is extremely unlikely for seafood like salmon to be
the carrier of the novel coronavirus, which was found on cutting boards
for imported salmon at Beijing's Xinfadi wholesale market, China's new
hot spot of COVID-19 infection. Beijing reported 36 new domestically transmitted cases on Saturday,
all having direct or indirect links to Xinfadi market, the biggest
wholesale food and vegetable market for the city. The market has been
shut down to curb the spread of COVID-19. Zeng Guang, a senior researcher at the Chinese Center for Disease
Control and Prevention, said on Sunday that, based on preliminary
analysis of the two early cases, the coronavirus strain in the latest
outbreak is different from the ones found in China, and early data
suggest it is a mutated variety from Europe. However, Zeng stressed that people should take this finding with a
grain of salt as more testing is being conducted to confirm the origin
of virus. Wu Zunyou, the chief epidemiologist at the CDC, said in a statement
on Saturday that fish in their natural habitat cannot catch coronavirus,
however, they can be contaminated by workers during capture or
transportation. China imports about 80,000 tons of cooled and frozen salmon each
year, according to news site Jiemian.com. Chile, Norway, the Faeroe
Islands, Australia and Canada are the main sources of salmon imports. Wu said that it cannot be concluded that salmon is the source of
infection just because novel coronavirus was detected on cutting boards. "Our seafood products are typically stored and transported in cold
containers, thus it is possible for the virus to be preserved for a long
time and increase the likelihood of infecting people," he said. Wu said Beijing's new outbreak could have two possible explanations.
The first may be the influx of meat and seafood to the market from all
over the country and around the world. Some of it may have been
contaminated by workers during processing and transportation, then the
virus jumped from produce to people. The second possibility is person-to-person transmission. "The
infected person who brought the virus into the market might be
asymptomatic or have very mild symptoms, and the hustle and bustle of
the market led to the cluster of new infections," he said. Wu said there is no need to panic as Beijing has moved swiftly to
contain the outbreak. "The know-how accumulated over the last few
months, and with the use of advanced technologies like big data, has
served us well in our contact tracing and diagnosis initiatives," he
said. "The valuable information we are collecting will be instrumental in
Beijing's prevention efforts, and may even reveal new insights into the
mysteries of the virus' mode of transmission," he added. Gao Xiaojun, spokesman for the Beijing Health Commission, said on
Saturday that of the 40 environmental samples collected from the market
that were later tested to contain the virus, only some came from salmon
cutting boards. A preprint study by the University College London last month found
that the novel coronavirus strain can infect humans and a broad range of
mammals, but not fish, birds or reptiles. In April, a study published on the journal Asian Fisheries Science
stated that the novel coronavirus is a type of betacoronavirus that can
only infect mammals. Moreover, the virus mostly impacts the respiratory
system, which most fish do not have. This means the virus is extremely
unlikely to infect and multiply in fish.
|