Hong Kong medical experts have discovered the Wuhan pneumonia disease can be transmitted between humans after a woman was apparently infected by her husband.

Hong Kong medical experts made the announcement after returning from Wuhan.

Of the 41 confirmed cases of the Wuhan disease, a man who worked in the Huanan Seafood Market showed pneumonia symptoms five days earlier than his wife, Cheung Chuk-kwan, the director of Communicable Disease Division, Centre for Health Protection, said in a Hong Kong media briefing on Wednesday.

Because the woman did not go to the wet market, she was either infected directly by her husband or by an item he brought home from the market, Cheung said.

About 70% of the 41 cases had visited or worked in the Huanan Seafood Market, while the remaining 30% were unsure if they had visited had not been to the wet market, she said.

Apart from the couple, a man and his son plus a relative who was living with them were also infected, but they were less likely to be human-to-human transmissions as they had symptoms at a close time, she said. People who did not visit the wet market could be infected by touching some contaminated items, she said.

In the wet market, the new coronavirus was found in samples on the floor, tables and gloves near the seafood stores, instead of the wild animal stores that sell birds, guinea pigs, snakes, badgers and hedgehogs, Cheung added.

The 41 infected patients were aged between 20 and 70, while most were male aged between 40 and 69, she said.

Cheung said the incubation period of the Wuhan disease could be several days to two weeks. She said it would be better to let the mainland experts comment on the infectivity of the disease as they were analyzing it.

Chun Tak-yi, the Under Secretary for Food and Health who also joined the two-day visit to Wuhan that ended Tuesday, said the Hong Kong representatives, together with those from Macau and Taiwan, had two meetings with the Wuhan medical team during the visit. He said the tour was not open to Hong Kong media due to its tight schedule.

According to RTHK, a group of Hong Kong TV reporters and their crews were taken to a police station in Wuhan after they took videos of the Huanan Seafood Market. They were only released after they agreed to delete their footage.

Chan added that the current preventive measures in Hong Kong, including temperature checks on incoming tourists, were on the right track. He said a rapid diagnostic test would be launched as early as possible.

The Hong Kong medical experts’ media briefing came after the Wuhan Health Commission made a statement published on its website on Wednesday morning.

According to the statement, a “limited human-to-human transmission” of the new coronavirus was possible, although the risk of a sustained human-to-human transmission remained relatively low.

The commission mentioned the case of the couple, but not that of the three family members. It said its medical experts were studying the disease with clinical and epidemical data. It added that it was checking the environment in other wet markets in the city. No community outbreak had happened.

In a previous statement, the commission said it received a report from authorities in Thailand about a sick Chinese woman. It said the woman had been isolated and was in a stable condition, while those who had close contact with her were under medical observation.

On Monday, a 61-year-old Wuhan woman was quarantined after landing in Bangkok as she was diagnosed with a pneumonia-like virus.

On Tuesday, Maria Van Kerkhove, the acting head of the World Health Organization’s emerging diseases unit, told Reuters that “it is possible that there is limited human-to-human transmission, potentially among families, but it is very clear right now that we have no sustained human-to-human transmission.”

The WHO said it was preparing for the possibility that there could be a wider outbreak.