An unidentified virus has struck dozens of people in Wuhan, the most populous city in Central China.
At least 59 cases have been confirmed so far, including seven patients who are critically ill, according to the Wuhan Municipal Health Committee. A further 163 people are also under medical observation after coming into close contact with the infected people.
Hong Kong authorities have activated a “serious response” level in reaction to eight possible cases of an illness they believe to be associated with visitors from the mainland Chinese city, reports the Associated Press.
All of the patients have fallen sick with pneumonia or severe respiratory tract infections, with many experiencing fever and breathing difficulties, although the source of the illness is not yet known.
There was speculation that the outbreak could be linked to SARS, the respiratory illness that started in China in 2002 and went on to kill over 700 people around the world. However, local health authorities have since ruled this out. They have also excluded the possibility of regular influenza, avian flu, adenoviruses, and Middle East Respiratory Syndrome (MERS).
The earliest case was reported on December 12, 2019, and the number of patients is continuing to grow. Many of the sick work at South China Seafood City market in Wuhan, which has been closed for sanitation and disinfection since January 1. Along with fish and seafood, the large wholesale market is also said to sell wild animals, such as rabbits and pheasants.
“Citizens should pay attention to maintaining indoor air circulation, avoiding closed and airless public places and crowded places, and wear masks if necessary,” Wuhan health authorities said in a statement.
According to the World Health Organization, the strong link to the market suggests that the illness is caused by a virus that spreads between animals and humans. This is what’s known as a zoonotic disease and includes most human infectious diseases, from swine flu and salmonella to Ebola and HIV.
So far, local health authorities say lab tests have shown there’s no evidence of significant human-to-human transmission and no health care worker infections have been reported.
However, the head of the University of Hong Kong's Centre for Infection, Ho Pak-leung, has thrown doubt on this claim by saying it’s “highly possible” that the illness is spreading from human to human. He also warned that there could be a surge in cases during the upcoming Chinese New Year on January 25.
“It is highly unlikely that this will lead to a major 2003-like epidemic, though we cannot be complacent,” said Yuen Kwok-yung, a microbiologist at the University of Hong Kong, according to TIME.