Updated: Apr 16, 2020
Asian countries risk new waves of coronavirus infections when they lift lockdowns. The same could happen in the rest of the world.
The two-month coronavirus lockdown in Wuhan, China is set to end on April 8, but the city could see yet another devastating wave of infections after that.
Italy has imposed similar measures — its outbreak is now the largest outside China, and its death toll is far higher than China's. Other countries have followed suit, too.
Since Wuhan's historic shutdown began on January 23, China has seen a sharp drop-off in its rate of new cases. The country reported no new local infections for the first time on March 19. On Wednesday, it began allowing residents of the Hubei province — outside the region's capital city of Wuhan — to start leaving if deemed risk-free. Elsewhere in China, classes are resuming and businesses are reopening.
But some experts fear that lifting those restrictions could start the whole process over again.
Lockdowns merely delay the outbreak's peak by about three months, Dr. Ben Cowling, an epidemiologist at the University of Hong Kong who researches influenza transmission and control measures, told Business Insider.
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"What happened in Wuhan and now what's happened in north Italy is not the peak of an epidemic. That's about a month away from the peak," he said. "They are still facing now, most likely, a second wave in one to two months' time. So are they going to shut down again?"
Travelers and asymptomatic people spread new waves of infection
A passenger returning from London wears a protective suit at Hong Kong International Airport, March 17, 2020.Tyrone Siu/Reuters
There are two main ways the virus can make a resurgence as residents emerge from their homes, return to work, take their children to school, and go shopping.
First, a small number of residents who were under lockdown could still have the virus when restrictions lift but not know they're sick. Those people could then spread it, starting a new wave of infections.
Second, international travelers could bring the virus back into the country.
The latter already seems to have led to a surge of new infections in Hong Kong.
Hong Kong's outbreak consisted of just 100 cases at the beginning of March; the city had implemented widespread social distancing, work-from-home rules, public-information campaigns, and high-tech case mapping. On March 2, civil servants went back to their offices. Two weeks later, the city reported a jump to 160 COVID-19 cases.
Then last week, as residents who had been abroad began returning home, Hong Kong's cases more than doubled. As of March 25, it has reported 410 cases of the new coronavirus.
"This is a pattern playing out across parts of Asia — mainland China, Singapore, Taiwan — that were among the first to tackle the outbreak," CNN analyst James Griffith wrote Monday. "All are now introducing new restrictions as a sudden wave of renewed cases begins to crest."
A couple walks past a temperature screening check at Changi International Airport in Singapore on February 27, 2020.Getty Images
Hong Kong Chief Executive Carrie Lam said the city has already weathered its first two waves of the virus.
"The first wave was the worries of transmissions from mainland (China), so we have put in a lot of measures," Lam said Saturday, according to CNN. "The second wave was the local transmissions, with those clusters arising from dinners and other things. Now we are facing the third wave."
Hong Kong's newest restriction, announced Monday, is that non-residents are not allowed to enter the territory. The city also sent civil servants back home and implemented testing requirements for anyone entering the city. Lam also requested that bars and restaurants stop selling alcohol.