China Is About to Find Out Whether Its Mass Quarantine Worked
(Bloomberg) -- In the last two weeks, China locked down some 50 million people in more than a dozen cities to try and stop the new coronavirus that has sickened thousands in the province of Hubei.
It may take as long as 14 days for the flu-like symptoms of the virus, dubbed 2019-nCov, to appear. Soon, China will find out if the largest mass quarantine in history has worked, or if undiscovered cases have quietly dispersed and seeded a far wider epidemic.
The travel restrictions in Hubei’s 11-million-person capital of Wuhan began on Jan. 23—eventually halting air and rail travel, buses, subways and car services. The lockdown came days before the Lunar New Year, China’s mass national holiday when people visit home or vacation. The aggressive plan aimed to keep the disease mostly in Hubei, slowing a viral diaspora officials feared could be carried invisibly by millions of Chinese travelers.
“China’s doing a great experiment to see if they can have an impact on international spread and national spread,” said David Heymann, head of the Centre on Global Health Security at Chatham House, an international affairs think tank. “You must set up a system to monitor and evaluate and see whether or not it’s effective,” he said during a press conference in London Tuesday.
In Hubei, the infection continues to grow and there are at least 13,500 cases, though some estimates have put the figure far higher. There is “intense human-to-human transmission,“ said Sylvie Briand, director of Global Infectious Hazard Preparedness for the World Health Organization. Around the world, more than 20,000 people have been infected and over 400 have died.
“Outside Hubei, we see spillover cases, people who were mostly infected in Hubei before there was a lockdown,” Briand said at a press conference in Geneva this week. “We would like to make sure we don’t have a second Hubei.”
A surge in new infections outside Hubei would be a sign that the coronavirus escaped to a greater degree than it already has. It would also confirm fears of public health leaders in the U.S. and elsewhere outside China, who have said they’re preparing as if the virus will eventually take hold abroad.
A wider increase in cases also has the potential to devastate financial markets, whose resilience in the face of the threat is striking some as foolhardy. U.S. stocks, already trading at some of the highest valuations in two decades, have pared or erased losses from the outbreak’s first weeks. After falling to five-month lows, Treasury yields started this week with the biggest increase since early December.
Experts are also trying to assess whether a critical mass of people left Wuhan and Hubei before the travel restrictions were put in place. An international team of researchers built a model using cell-phone location data from prior Lunar New Year holidays, which showed wide patterns of travel ahead of the holiday in past years—suggesting the same could have happened during the cornonavirus outbreak.
“These silent importations may have seeded sustained outbreaks that have not yet become apparent,“ the researchers said in a paper scheduled to be published in the journal Emerging Infectious Diseases, which is affiliated with the U.S. Centers for Disease Control and Prevention.
The researchers estimated that in the two weeks leading up to the quarantine, there were about 10 million trips to Wuhan from other cities, and 12.5 million trips from Wuhan to elsewhere. The group also estimated that there may have been thousands more cases at the time of lockdown, never diagnosed.
“This is a huge college town. Some of this is students leaving and coming back,” said Lauren Ancel Meyers, a mathematical epidemiologist at the University of Texas at Austin and one of the authors of the paper. As to whether the quarantine was effective, “We just simply don’t know yet.”
The disease’s similarities to the flu virus are almost certain to make it difficult to contain. Every year, the flu sweeps around the globe, infecting millions. Governments and public health groups long ago gave up trying to stop it entirely, focusing on mitigating its harm.
The same may happen with the now coronavirus, said Michael Osterholm, the director of the Center for Infectious Disease Research and Policy at the University of Minnesota’s medical school, and an expert on biosecurity and epidemics.
“This is more and more like flu, which is like trying to stop the wind,” Osterholm said in a telephone interview. “The seeding is out there. It’s going to take off, there’s more than enough matches thrown into the forest to set it on fire.”
Chinese authorities’ best bet is to slow the disease there, not stop it. Osterholm said the real question is whether the coronavirus takes hold outside of China.
“Four to six weeks from now,” Osterholm said, “we’re going to know.”
©2020 Bloomberg L.P.