Testing international travellers on arrival with a follow-up test one week later detects 94 per cent of COVID-19 cases, according to a recent study at YYZ and researchers say the findings show a robust testing program would be a reasonable alternative to Canada’s current mandatory two-week quarantine.
University of Toronto and McMaster University researchers, in partnership with Air Canada and the Greater Toronto Airports Authority, conducted the study at YYZ in SEP and OCT 2020 to determine the feasibility of an airport testing program.
Of the 16,361 international travellers enrolled in the study, 248 or 1.5 per cent tested positive for COVID-19. Of these, 67 per cent were identified on arrival, 27 per cent on day seven and six per cent on day 14.
Nearly 75 per cent of the travellers who tested positive for COVID-19 were coming from areas designated high-risk like the United States., India and Mexico. The positivity rates were also high for travellers from countries in Africa, a region with lower levels of testing.
“What our results show, which is consistent with the results from some of the mathematical models that have been done, is that with a reduced quarantine strategy and test at day seven, you pick up as many cases from the population as you do with a perfect 14-day quarantine,” says Vivek Goel, the study’s first author and a professor at U of T’s Institute of Health Policy Management and Evaluation (IHPME) at the Dalla Lana School of Public Health.
The findings speak to the need for border testing when travel restrictions are lifted, he notes.
“It shows that as we get vaccines implemented in Canada, testing at the border is going to remain very important because we’re going to have disease continue to circulate in other parts of the world where they may not actually be picking it up.”
A two-week quarantine is not only a significant barrier to travel, but also has economic, social and psychological consequences, argues Goel, adding that there is evidence of “decline in general well-being during the time that people were in quarantine in their home.”
The results of the study were recently published to a pre-print server while they await peer review.
As of 22FEB, a Canadian health order requires air travellers to quarantine for three days at an airport hotel at their own expense while awaiting results of their arrival COVID-19 test. Those with a negative result can finish the rest of their mandatory 14-day quarantine at home. The government also mandated Canadian tour operators to cease flights to the Caribbean and Mexico until 30APR.
