China says the Wuhan virus, unlike SARS, is infectious during its incubation period

Trying to stop the coronavirus from spreading.
Trying to stop the coronavirus from spreading.
Image: AP Photo/Mark Schiefelbein
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The Chinese government warned today (Jan. 26) the new coronavirus spreading through the country appears to be contagious as much as two weeks before symptoms appear. In a press briefing, the head of China’s National Health Commission, Ma Xiaowei, said scientists’ understanding of the virus was still “limited” and the outbreak was likely to continue for “some time,” according to the South China Morning Post.

Most of the patients originally diagnosed with the virus were exposed at the Huanan seafood market in Wuhan, which also trades in wild animals believed to be the source of the infection. Genetic analysis suggests the new coronavirus originated in fruit bats, according to China’s Centre for Disease Control and Prevention. That gives it a common ancestor with the SARS (severe acute respiratory syndrome) virus. The SARS outbreak in 2002-03 infected thousands and killed more than 740 people around the world.  While people infected with SARs generally developed symptoms within a week of infection, Ma warned that people with the new coronavirus could be contagious for as many as 14 days before showing signs of infection.

Globally, around 2,000 cases, and 56 deaths, have been reported, the vast majority in China. While the virus now appears to be spreading efficiently between humans, health officials in the United States caution that casual contact with an infected person posted a “minimal risk for developing infection.”

Wuhan, a city in central China, is at the center of the outbreak. The local government described the new virus as “preventable and controllable” at the beginning of the outbreak, but the Chinese government has since quarantined the city of 11 million people, and banned travel from at least a dozen more, an unprecedented move. It is dispatching more than 2,300 medical professionals to battle the outbreak. But experts said China’s quarantines would have been far more effective if they had acted earlier.

So far, the virus has spread to several provinces in China, with a few reported cases in China, Thailand, Japan, South Korea, and the US. The first case was detected as early as Dec. 1, about three weeks before the Wuhan government’s announcement of a cluster of pneumonia-like infection on Dec 31. Of the 41 original patients with the virus, most recovered but six have died, according to an analysis by The Lancet. Among the original patients, a median of eight days passed between the onset of symptoms and respiratory distress (dysponea). All patients developed pneumonia.

The Wuhan virus’s pattern.
The Wuhan virus’s pattern.
Image: The Lancet