The Hong Kong government has been urged by infectious disease experts not to rule out the possibility that the unknown pneumonia disease in Wuhan could be transmitted between humans.

Based on the speed with which the Wuhan disease has spread, there has not been any evidence of human-to-human transmission, said Ho Pak-leung, Director of the University of Hong Kong’s Center for Infection.

However, if human-to-human transmission should turn out to be possible, emergency measures to stop virus carriers from visiting Hong Kong would be difficult due to a high flow of people between the city and the mainland, Ho said.

The Hong Kong government should take all possible measures to avoid the disease’s transmission between humans and educate the public about public hygiene, Ho said.

Ho said the Wuhan government should disclose the DNA test results of the unknown disease as early as possible so that overseas medical institutions can have better preparations.

It was too early to say whether the Wuhan disease could be transmitted between humans as the first infection was only identified on December 12, said David Hui Shu-cheong, chairman, Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong.

Citing medical experts in the mainland, Hui said it was likely that the unknown disease in Wuhan was caused by a new kind of coronavirus similar to the severe acute respiratory syndrome, or SARS, outbreak in 2003.

Hui said it would take several weeks for the mainland authority to figure out the DNA sequence of the Wuhan virus.

As of 8pm on Sunday, The Wuhan Municipal Health Commission said in a statement, it had identified 59 people who were infected by an unknown pneumonia disease. Among them, seven cases were serious. The commission also said it had traced 163 people who were close to the patients and would continue the contact tracing.

The commission said some patients were sellers in the Huanan Seafood Market in Wuhan. No medical staff was infected while no human-to-human transmission was identified. Until now, influenza, avian influenza, adenoviruses, SARS and Middle East Respiratory Syndrome, or MERS, have been ruled out as the cause of the infections. No death case was reported.

On Tuesday morning, some representatives of The Democratic Alliance for the Betterment and Progress of Hong Kong (DAB), a pro-Beijing political party, met the central government’s Liaison Office deputy director, He Jing, and called on the mainland government to disclose information on the Wuhan disease on a daily basis. He said the Liaison Office would forward the request to the mainland.

On Monday, Hong Kong’s Center for Health Protection announced that a total of 21 cases of respiratory-related infections had been reported over the past one week. Seven people have recovered and left hospitals. The center also listed out the cause of the 21 infections and found out that most cases were related to influenza and some other respiratory viruses. Only five cases did not show any positive laboratory results to the known diseases.

On Tuesday, Chief Executive Carrie Lam said there had not been any confirmed cases related to the Wuhan disease in Hong Kong. She urged the public not to believe in online rumors that some public hospitals had tried to cover up the infection numbers.

Lam added that the government would try to amend the list of infectious diseases in the Cap. 599 Prevention and Control of Disease Ordinance this week to include the unknown Wuhan disease so that hospitals would have the power to mandatorily isolate the patients.

According to the Hospital Authority, Ruttonjee Hospital in Wan Chai received a mainland woman patient, who had contracted fever after arriving from Wuhan on Saturday. The woman began her journey from the northeastern region of China on January 1 and arrived in Wuhan last Friday. She then suffered from coughing and fever. As the Department of Health failed to issue an isolation order due to the loophole on the infectious disease list, the woman was allowed to leave the hospital at 11pm on Sunday.

In recent days, more and more people started wearing masks in public places as they were worried about the Wuhan disease. Some grocery shops doubled the prices of the masks but still saw strong demand from buyers.