China continues to refuse to release animal sampling testing data
- Xiang Zhang
It has been two months since the outbreak of the coronavirus in Wuhan and its spread has shown no signs of slowing down in China. More than 35 Chinese cities have been put on lockdown by Chinese authorities in an attempt to isolate confirmed and suspected cases. The lives of millions of people are in danger as the virus shows signs of spreading further in China as well as internationally.
There are significant gaps in the official investigations into the origins of the novel Coronavirus. In order to contain the virus, one first needs to understand how a virus that allegedly originated in animals found its way to humans. For this to happen, the Chinese authorities need to release their animal testing data and samples. Testing results from animal samples collected at epicenters would give important insights into what animals might serve as intermediate hosts for the new coronavirus.
This is critical to the containment of the epidemic. For example, if rats are the intermediate hosts for this virus, it would be futile to shut down the cities to restrict people’s movements while infected rats are still moving freely. Results from animal samples could also guide policy decisions that would reduce the risk of another outbreak.
An Animal Origin of the Virus
Scientific studies based on phylogenetic analysis have researched the sequence of the novel coronavirus, compared it to other coronavirus sequences, and found it likely originated in bats. Researchers from the Wuhan Institute of Virology found the genome in the virus found in patients was 96 percent identical to that of an existing bat coronavirus, according to a study published in the journal Nature. But there have been other theories as well. One Chinese study suggested, for example, that snakes were the source of transmission to humans. However, many scientists believe that reptiles are a less likely source and that mammals like rats and pigs, and some birds, have been the primary reservoir for coronaviruses.
With this in mind, phylogenetic studies of viral genome sequences need to be supported by animal studies to confirm the origin of the infection, as well as to determine whether there is an intermediate host.
It is not an easy task for a virus to establish zoonotic transmission, and coronaviruses rarely leap from animal to human infection with high transmissibility. There is even less chance to see a coronavirus leap directly from bats to humans. To infect new hosts, mutations need to occur with the viral surface proteins and/or envelope and structural genes, so that the mutated viruses can bind and enter the cells of new species, and efficiently complete the replication cycles in the new hosts.
Some scientists have argued that coronaviruses can jump directly to humans, without mutating or passing through an intermediate species. However, an intermediate host was clearly needed to establish zoonotic transmission to humans in the previous outbreaks of coronaviruses. Many studies suggested that the bat coronavirus jumped from its natural host bats to civets and then to humans during the 2003 SARS outbreak, and it jumped from bats to camels and then to humans for the MERS outbreak. So, civets and camels would serve as intermediate hosts for zoonotic transmission.
Because bats were not sold at the Huanan market in Wuhan—the epicenter of the infection—at the time of the outbreak, this suggests the existence of another intermediate animal host that may have transferred the virus to humans.
What is the most puzzling is that there have been no reports on the testing of animal samples collected in any epicenters in Wuhan, especially at the Huanan seafood market, to identify what animals might be the host or intermediate hosts of this novel Wuhan coronavirus. …