Experts are zeroing in on these and other questions, but clear answers are not yet at hand.
– The Toll So Far –
As of Wednesday, some 6,000 cases have been confirmed in China, its country of origin, with at least 132 fatalities.
No deaths have been attributed to the virus outside China.
The 2002/03 SARS outbreak (Severe Acute Respiratory Syndrome) started in Guangdong Province and killed 774 people out of a total 8,096 infected. The 2012 MERS outbreak (Middle East respiratory syndrome) killed 858 people out of the 2,494 infected.
The seasonal flu, by comparison, kills 290,000 to 650,000 people per year, according to the World Health Organization (WHO). In the United States, the mortality rate among people infected with influenza is about 0.13 percent, the Centers for Disease Control has calculated.
– How Contagious ? –
Estimates of how easily coronavirus spreads range from a “base reproduction rate” of 1.4 to 3.8 people infected by a single patient, according to David Fisman, a professor at the University of Toronto.
“If that proves to be accurate, it would in part explain the surprisingly swift growth of cases in Hubei and beyond, and suggests that China is in for a very rough ride,” said Stephen Morrison from the Center for Strategic & International Studies in Washington.
Scientists at Britain’s Imperial College, meanwhile, estimate that each coronavirus patient infects on average 2.6 others — making it roughly as infectious as annual influenza outbreaks.
– When Is It Contagious? –
This crucial question remains unanswered.
“In my view it is premature to conclude, on the basis of the evidence currently available, that the new virus can be transmitted before symptoms appear,” said Mark Woolhouse, professor of Infectious Disease Epidemiology, at the University of Edinburgh.
“In the absence of any treatment or vaccine our main hope of controlling the epidemic is the rapid identification of cases and the immediate prevention of onward transmission through patient isolation,” he added.
– Person-to-Person Transmission –
Almost all cases of such transmission have occurred in China, but there have also been a handful of cases in Vietnam, Germany and Japan.
But that situation could be different in other parts of the world.
“If export occurs to countries in Africa and elsewhere where there are limited health security capacities, grave secondary outbreaks could emerge outside of China,” Morrison added.
– What Are the Symptoms? –
All patients had pneumonia, most had a fever, three-quarters of them were coughing and more than half had trouble breathing.
There are, however, some “important differences,” said lead author Bin Lao.
– Incubation Period –
As a precaution, health authorities in France and other countries have set an isolation period of 14 days for repatriated nationals and other people coming from the coronavirus hot zone.
– Avoiding Infection –
Health authorities and scientists say the standard precautions against viral illnesses are applicable: wash your hands frequently, cover up your coughs, try not to touch your face.
Anyone who does come down with the virus should be placed in isolation.
“Considering that substantial numbers of patients with SARS and MERS were infected in health-care settings”, precautions need to be taken to prevent that happening again, the Chinese team warned in The Lancet.