Jan 22: Tracking down the source and the infection route of the newly emerged coronavirus in the central Chinese city of Wuhan is akin to putting a jigsaw puzzle together, as the death toll rises and carriers of the pathogen emerge across the country and the world, according to a disease specialist.
“It’s early days, it’s a real jigsaw puzzle right now,” said David Heymann, professor of infectious disease epidemiology at the London School of Hygiene and Tropical Medicine.
“Right now, it doesn’t look like this is a particularly lethal virus. It’s lethal in people who have co-morbidities, elderly people who have diabetes and chronic lung disease, and that’s similar to what the influenza virus does,” said Heymann, a former executive director of the World Health Organisation’s Communicable Diseases Cluster, where he headed the global response to the Sars virus in 2002-03.
“What’s key to all of this is good infection prevention and control in hospital settings. If health workers continue to get infected now that they know this virus is present, they can inadvertently infect other patients,” he said.
China’s National Health Commission (NHC) said on Wednesday that tougher measures introduced this week authorised hospitals nationwide to quarantine any suspected carriers of the virus and their close contacts, even against their will. The coronavirus has killed 17 people – all of them in Hubei province – since it first caught the attention of medical authorities a little over three weeks ago. As of 11pm Wednesday, 541 people in mainland China had been infected, according to official reports.
“The basic [measures besides quarantine] are contact tracing, identifying people who might have been exposed, and making sure that they understand that if they develop a fever, they must immediately report to a health facility because that’s the time they become infectious,” said Heymann, who is chair of an advisory body to the WHO.
He said another measure was to isolate patients with the disease and take care of them until the immune system could rid the body of the virus. “There’s no other medicine right now that can treat it.”
Wuhan, in Hubei province, has remained the ground zero of fatalities and infections since the outbreak was first reported on December 31 and with no drugs available to fight the virus, containment and quarantine are the tools China is turning to to try and control it.
That had now reached a “most critical stage”, Li Bin, the director of the NHC, said on Wednesday.
China is also this week experiencing its largest single annual mass migration of people as hundreds of millions travel across the country for the Lunar New Year holiday.
Li, of the NHC, said there was a risk of the virus mutating and spreading further during the country’s annual peak travel period.
“The virus is mainly transmitted through the respiratory tract,” Li said. “Now, during Chinese New Year, the surge [in people moving around the country] increases the risk of the epidemic’s spread and the difficulty of prevention and control. We must not take it lightly.”
The virus, which has pneumonia-like symptoms, has most recently been discovered in travellers in Hong Kong and the US for the first time. Infected individuals have also been found in Taiwan, Thailand, Japan, South Korea and Macau, with most of the cases involving people travelling from Wuhan.
Closing down a city the size of Wuhan would be unprecedented in China, but the country’s top infectious disease expert said quarantine was the only way to stop the disease at present.
“As soon as it spreads from human to human, quarantine must be the first priority,” Zhong Nanshan said at a briefing on Tuesday. “At the moment, I don’t think quarantine has been implemented thoroughly enough.”
The disease is believed to have first appeared in a seafood and animal meat market in Wuhan.
The first cluster of infections in December involved people who worked at the market, suggesting that the virus had jumped from an animal host in the same way that the severe acute respiratory syndrome (Sars) epidemic began.
Gao Fu, director of China’s disease control and prevention centre, said at the briefing that the source of the disease was a wild animal sold at the seafood market, but did not elaborate on what species it was, or how the disease spread from animals to humans.
“We are in a gradual process of learning the development stages and characteristics of the virus,” said Jiao, who also paid tribute to front-line medical staff confronting the outbreak.
Heymann said it was not possible to make predictions of how the virus would proceed from now.
“Influenza viruses can’t be stopped, they run their course and they stop. It would be wrong to make any type of estimate of what might happen in future because not enough is known to base that estimate on. The WHO will be looking at all the evidence and making recommendations for the world to follow.”
-South China Morning Post