Coronavirus origin: Few leads, many theories in hunt for source

Coronavirus most likely to have jumped to humans from intermediary host, but some say lab accident cannot be ruled out.

Hong Kong, China - The blame game between China and the United States on the origin of the coronavirus pandemic has fuelled a host of theories, some more believable than others. 

At the start of the outbreak in December, the most mainstream assumption was that the virus originated from a so-called wet market in Wuhan, the Chinese city where the first COVID-19 cases were reported.

The practice of collecting viruses from bats first burst into public view in the early weeks of the outbreak when Shi Zhengli, a noted scientist with the Wuhan Institute of Virology, refuted a swirl of online accusations both at home and abroad that the coronavirus may have leaked from her institute, where a lab certified as BSL-4, the highest level for handling dangerous pathogens, opened three years ago.

Director-Generalof the World Health Organization Tedros Adhanom Ghebreyesu has called such speculation part of an "infodemic" of fake news surrounding the coronavirus, while other public health officials said they belong with the slew of conspiracy theories claiming that the virus was engineered (all scientists who have studied the genome of the virus agree that would be impossible). 

But some scientists, both within China and elsewhere, say an accidental leak remains a possibility - insofar as there is no evidence to disprove it.

"There is nothing 'fake' about lab accidents," said Richard Ebright, a molecular biologist and director at the Waksman Institute of Microbiology at Rutgers University in New Jersey, US. "There also is nothing 'conspiratorial' about lab accidents."

Experts from the World Health Organization (WHO) and Chinese joint team visited Wuhan, the city where the new coronavirus purportedly originated, in February when the outbreak there was at its peak [File: China Daily via Reuters]