Do claims the coronavirus spread to China via frozen food merit serious investigation?
- Some scientists in China have called for the WHO to investigate the cold chain theory, but it has been greeted with scepticism overseas
- There is no firm evidence to show the virus was present in other countries before the first Covid-19 cases were identified in Wuhan in late 2019
Chinese officials have insisted it could not have escaped from the Wuhan Institute of Virology, calling instead for the focus to shift elsewhere, including an examination of US labs and the cold chain theory.
Last week Liu Jun, from the National Institute for Viral Disease Control and Prevention, told Science and Technology Daily, that there was evidence from epidemiological studies and environmental sample-testing backing this theory, adding that the next step would be to launch international studies under the WHO.
He said these should trace back international suppliers to the Huanan market in Wuhan, which was linked to a number of the earliest known Covid-19 cases, and to carry out further research with source countries.
There is no conclusive evidence that the coronavirus was present in other countries before the disease was first identified in late 2019, but some studies have suggested it is a possibility.