Japanese man who returned from Wuhan with the novel virus infection did not visit the Huanan Seafood Wholesale Market or any other live animal markets in Wuhan. This raises the possibility that the virus have already acquired the ability to spread among humans.

A week after the World Health Organization (WHO) said that preliminary investigation indicates that the novel coronavirus identified in people in the Chinese city of Wuhan has “no significant human-to-human transmission, there appears evidence suggesting otherwise. A Japanese man who returned from Wuhan was found to be infected with the novel virus. According to the WHO, the person had not visited the Huanan Seafood Wholesale Market or any other live animal markets in Wuhan. In fact, he had come in “close contact with a person with pneumonia”.

“We are still in the early stages of understanding this new virus, where it came from, and how it affects people. There is still many unknowns, and the situation may continue to evolve,” the WHO tweeted on January 16. The next day the WHO said: “Not enough is known about the novel coronavirus to draw definitive conclusions about how it is transmitted, clinical features of disease, or the extent to which it has spread. The source also remains unknown.”

Based on preliminary epidemiological investigation, it was earlier said that most patients had come in close contact with animals or frequently visited a wholesale seafood market, which has been closed since January 1.

According to the WHO, 763 people, including medical staff, who have come in close contact with patients infected with the novel coronavirus have been identified for close monitoring. “At this stage, there is no infection among healthcare workers, and no clear evidence of human-to-human transmission,” the WHO said on January 12, 2020. It also said there is “no clear evidence” that the virus “easily passes” from one person to another.

Japanese patient confirms human spread

But the case of the Japanese patient, who has since been discharged from hospital, does indicate that the virus has already acquired the ability to spread from one person to another.

On January 16, the WHO tweeted: “The fact that some cases do not seem to be linked with the Huanan seafood market means we cannot exclude the possibility of limited human-to-human transmission. It added saying that there is “no clear evidence of sustained human-to-human transmission and there are no infections reported among health care workers”.

In more than one place

Another layer of complexity is in the place of origin of the infections. Earlier, the Huanan Seafood Market was considered as the place from where most people got infected. But the 61-year-old Chinese woman who had travelled from Wuhan to Thailand and was found to be infected with the virus had “not visited the Wuhan seafood market but another market where freshly slaughtered animals are sold”, the New York Times reported.

In a January 17 release, the WHO noted that the source of outbreak in Wuhan is still under investigation. And also said: “Preliminary investigations have identified environmental samples positive for nCoV [novel coronavirus] in Huanan seafood wholesale market in Wuhan City, however some laboratory-confirmed patients did not report visiting this market.”

As on January 17, there have been 45 cases of infection with the novel virus. Of them, 15 have been cured and discharged from hospital, five severe cases are being treated while two have died. None of the 763 close contacts being investigated have developed infection.