China virus outbreak will last months

The deadly new coronavirus that has broken out in China, 2019-nCoV, will afflict a minimum of tens of thousands of people and will last at least several months, researchers estimate based on the first available data.

“The best case scenario, you would have something… where we go through the spring into the summer, and then it dies down,” David Fisman, a professor at the University of Toronto who wrote an analysis of the virus for the International Society for Infectious Diseases, told AFP.

“It’s not something that’s going to end the next week or the next month,” said Alessandro Vespignani, a professor at Northeastern University. He is part of a group of researchers that manages an online dashboard about the outbreak.

Epidemiologists have no crystal ball. They have only piecemeal information on the new virus, which appeared in December. They use mathematical models to estimate the actual number of cases, as of the current date, and compare them to past outbreaks – but many of their hypotheses remain uncertain.

Until the past weekend, researchers thought that infected people were not contagious until they began exhibiting symptoms, such as fever, respiratory problems, and pneumonia. But Chinese authorities said on Sunday they had established the opposite.

US health authorities said on Monday they had not seen evidence that asymptomatic patients can infect other people. But if they can, this would definitely change the outbreak’s dynamics.

The first estimates for the length of the incubation period – about two weeks – are recent.

In recent days, multiple experts have calculated an important parameter for any outbreak: the basic reproduction number, or “R0.” It represents the number of people contaminated by an infected person. Estimates range from 1.4 to 3.8, according to Fisman, figures that are considered moderate.

That is only an average: some patients may infect many people, while others infect only a few. “On its own, it isn’t a reason to panic,” said Maimuna Majumder, a researcher at Harvard University and at Boston Children’s Hospital.-AFP.