'Slow and steady' approach key to preventing second wave of COVID-19: experts
TORONTO -- As life slowly returns to normal in Hubei province, China, the epicentre of the original COVID-19 outbreak, new modelling research suggests that lifting physical distancing measures prematurely could lead to a second wave of cases later this year.
The research, published in The Lancet Public Health journal Wednesday, used mathematical modelling to simulate the impact of extending or relaxing current school and workplace closures in the city of Wuhan, the capital of the Hubei province.
Researchers estimated that by lifting these control measures in March, a second wave of cases could occur by late August. But maintaining restrictions until April could delay a second peak until October, allowing the region’s health services to rebound from the original outbreak.
“The unprecedented measures the city of Wuhan has put in place to reduce social contacts in school and the workplace have helped to control the outbreak,” lead researcher Dr. Kiesha Prem said in a statement.
“However, the city now needs to be really careful to avoid prematurely lifting physical distancing measures, because that could lead to an earlier secondary peak in cases. But if they relax the restrictions gradually, this is likely to both delay and flatten the peak.”
Chinese authorities lifted the lockdown in place across most of Hubei province Tuesday, allowing some 58 million people to leave their homes for the first time in months.
Wuhan, the city of 11 million people where the novel coronavirus was first detected in late December, will stay locked down until April 8.
What could this mean for Canada?
The research, though merely an estimation, presents an interesting case for other countries battling their own COVID-19 outbreaks, including Canada.
“We can’t let down our guard once transmission rates seem to stop and the number of infections and deaths start decreasing. As soon as you lift the social distancing measures, you’re basically allowing the disease to start spreading again,” Dionne Aleman, associate professor of industrial engineering at the University of Toronto, told CTVNews.ca by phone after looking at the study’s findings.
“You almost create a false sense of security when the social distancing measures are working. Once everybody starts going back to their normal lives and a few people are still infected, the disease just picks up again.”
Aleman’s research focuses on building simulations to predict the spread of a pandemic disease in an urban population, otherwise known as pandemic models.
She says in order to successfully flatten the curve of the disease, Canadians should expect to heed physical distancing instructions for several months.
But she notes that it would be in the best interest of public health and safety if the government slowly relaxes some of the measures in place once the outbreak is under control.
“If we let people start intermingling in parks and let that go on for a couple of weeks… if everything seems like it’s under control then maybe we think about opening schools. If that’s going well then we consider opening workplaces,” she explained.
“I do think that a ‘slow and steady wins the race’ approach is the right way to go to make sure that the disease doesn’t ramp up again and have another big peak.”
Aleman adds, in her opinion, the wisest public policy decision would be to cancel the remainder of the school year for Canadian children, noting that students are only a couple of months away from that deadline to begin with.
Ontario Premier Doug Ford has already announced that students will not be returning to school on April 6, as the province first hoped, acknowledging that the scheduled back-to-school date is unrealistic.
“Two or three months is not a whole lot of time when it comes to a disease that spreads as quickly, and in some cases as silently, as COVID-19,” said Aleman.
“There are lots of asymptomatic spreaders, and there is no way of telling who they are because there is no reason to suspect they are infected.”
Researchers behind the recent modelling caution that given the large uncertainties surrounding the virus -- including how many people an infected person is likely to infect and the average length that a person is infected for -- the true impact of relaxing physical distancing measures “cannot be precisely predicted.”
In the study, researchers developed a transmission model to quantify the impact of school and workplace closures using information about how often people of different ages mix with each other in different locations using the latest data on the spread of the virus in Wuhan and greater China.
But researchers note the results of the study would vary in different countries.
“Our results won’t look exactly the same in another country, because the population structure and the way people mix will be different,” study co-author Dr. Yang Liu said in a statement.
“But we think one thing probably applies everywhere: physical distancing measures are very useful, and we need to carefully adjust their lifting to avoid subsequent waves of infection when workers and school children return to their normal routine.”