The World Health Organization said Monday it remained unclear if the deadly coronavirus spreading in China and beyond is contagious during its incubation period, before symptoms appear.
The virus, which can cause a pneumonia-like acute respiratory infection, has in a matter of weeks killed more than 80 people and infected some 2,740 in China, while cases have been identified in more than a dozen other countries.
In a fresh report on the new virus, known as 2019nCoV, the UN health agency said current estimates put the incubation period for the virus at between two and 10 days.
"Understanding the time when infected patients may transmit the virus to others is critical for control efforts," WHO said.
It did not immediately confirm assertions made by Chinese authorities that people who are infected can spread the disease before they show any symptoms of fever or respiratory difficulties.
"Detailed epidemiological information from more people infected is needed to determine the infectious period of 2019nCoV, in particular whether transmission can occur from asymptomatic individuals or during the incubation period," it said.
WHO last week stopped short of declaring the outbreak a public health emergency of international concern — a rare designation used only for the worst outbreaks that would trigger more concerted global action.
But the world body admitted Monday it had made an error in its risk assessment for the deadly virus in several reports last week, acknowledging the global risk was "high" rather than "moderate".
The virus has caused global concern because of its similarity to Severe Acute Respiratory Syndrome (SARS), which killed hundreds across mainland China and Hong Kong in 2002-2003 and was also traced to the wild game trade.
The new virus is believed to have jumped to people from animals in a Wuhan market, but it has since begun spreading between humans, although the exact mode of transmission has yet to be confirmed.
As with SARS and another deadly coronavirus known as Middle-East Respiratory Syndrome, or MERS, WHO suggested that the new virus could be spreading through droplets, for instance when people sneeze or cough, or through direct contact with infected people or with objects they have touched.
To reduce the risk of infection, WHO stressed the need to avoid close contact with people suffering from acute respiratory infections, frequently wash one's hands, and avoid unprotected contact with farm or wild animals.
The agency also stressed the importance of practising so-called cough etiquette, including maintaining distance and covering coughs and sneezes with tissues.
WHO has not recommended any international travel or trade restrictions, but does call for high levels of vigilance, including encouraging airport exit and entry screening for passengers leaving affected areas to check for fever and coughs.
China's coronavirus has not mutated in the US, says CDC
Washington (AFP) Jan 27, 2020 –
US health authorities said Monday they have sequenced the genome of the first two cases of the Chinese coronavirus reported in the country and confirmed the virus has not mutated since leaving China.
Nancy Messonnier, head of respiratory diseases at the Centers for Disease Control and Prevention (CDC) said she was planning imminent changes on measures to control and track the deadly virus, beyond the current restrictions just on travelers arriving from the city Wuhan, which is at the epicenter of the outbreak.
"Right now, and based on CDC's analysis of the available data, it doesn't look like the [virus] has mutated," she said in a telephone news conference.
"All the sequences we've extracted are similar to the one that China initially posted a couple of weeks ago," she said.
All passengers arriving from Wuhan are currently subject to testing in five US airports, but since China has suspended all flights out of the stricken city, there are fewer and fewer travelers from there arriving in the US.
The virus has also reached other Chinese provinces and China has announced that people who are infected can spread the disease before they show any symptoms of fever or respiratory difficulties.
That has rendered redundant the current measures to contain the virus in the US.
"I expect that in the coming days, our travel recommendations will change," said Messonnier. "I expect there will be a decision, and an announcement about that within the next day."
Despite that, the CDC still estimates the risk from the virus to Americans to be low.
"At this time in the US, this virus is not spreading in the community," Messonnier said.
There have been five confirmed cases in the country and 110 patients have either been under observation or are currently being tested in 26 states. Aside from the five who so far tested positive, 32 have tested negative.
It takes around a day to receive the test results from suspected cases because blood samples have to be sent to the CDC headquarters in Atlanta, Georgia.
