Risk of Coronavirus Transmission Found Higher in Wildlife Trade Supply Chain

For those in the wildlife trade supply chain, a higher risk of coronavirus transmission has been found. In Vietnam in 2013-2014, a high coronavirus presence was found in rodents and bats, as well as in the wildlife trade supply chain, including large markets and restaurants.

This is the finding of the study published by a research team last August 10 in PLOS ONE. Wildlife Conservation Society's Amanda Fine and the other authors noted that coronavirus amplification in the wildlife trade supply chain suggests a higher risk for consumers. This also likely caused the transmission of the coronavirus into human populations.

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The Coronavirus Threat

The emerging and re-emerging outbreaks of coronavirus infections during the last 20 years and the current COVID-19 pandemic from SARS-CoV-2 or severe acute respiratory syndrome coronavirus 2 is a clear indication of the coronavirus family's importance as a public health threat.

In China, the contact between people and wildlife such as bats, rodents, and any species of the intermediate host was certainly determined to be the trigger of the COVID-19 zoonotic transmission. The current scientific evidence points to the involvement of the wildlife markets, which ultimately led to the worldwide or pandemic spread of the COVID-19 virus.

Outside of China, particularly in Vietnam, commercial farming of wildlife is robust. It forms a section of the international expanded trade in wildlife that has been thought to be the source or the contributor to global viral epidemics. These epidemics include deadly viruses such as Ebola, SARS, HIV, and the like.

The Investigative Study

The researchers wanted to more deeply understand and track the natural coronavirus hosts and the risks of human and wildlife interactions that facilitate the transmission of the virus from animals to people.

To do this, the research team investigated coronaviruses' presence and the diversity in species of wildlife in the human-wildlife interfaces in Vietnam during the years 2013 and 2014. These were the years that preceded the emergence of the SARS-CoV-2 virus. The researchers looked into the high proportions of positive coronavirus infections in field rats harvested for humans' consumption.

Results of the Study

The results showed that 34 percent were positive of infection, or 239 out of 702 samples. The study also looked at the bats from guano farms. A 74.8 percent positive result from bats was shown, where 234 out of the 313 animals sampled by the study had the virus. These farms were adjacent to residential areas.

The detection of coronavirus infections grew increasingly higher along the wildlife trade supply chain: the field rats from traders are 20.7 percent positive (39 rats out of 188 samples); the rats in large markets are 32 percent positive (116 rats out of 363 samples), and the rats being served in restaurants are 55.6 percent positive (84 out of 151).

The coronaviruses were also found in rodents in wildlife farms (60.7 percent positive). Malayan porcupines (6 percent) and bamboo rats (6.3 percent) farmed for consumption were also positive.

What's Next?

To lessen the risk to public health from emerging viral diseases, the researchers recommended the improvement of coronaviruses' surveillance in wildlife and reform in the wildlife trade.

The study also showed that the wildlife trade supply chain increases the contact between people and wildlife, amplifying the number of infections in animals.

Tags coronavirus, Wildlife Trade Supply Chain