Travel-related COVID spread in Ontario may be worse than we realize

In announcing new province-wide pandemic restrictions on Monday, Premier Doug Ford told Ontarians that COVID-19 is spreading between regions. “Unfortunately, despite the restrictions, we’ve seen a growing number of people travelling between regions within Ontario. COVID is spreading rapidly from high-outbreak areas to areas with fewer cases. As it does, our hospitals are filling up more each day.”

As the holidays near, officials in the Hamilton and Niagara area say curtailing travel and socialization will be crucial to avoid a Christmas spike in coronavirus infections.  

Dr. Mustafa Hirji, Niagara’s acting medical officer of health, says this holiday season, everyone should stay home. He tells TVO.org that traveller spread is a source of COVID-19 transmission in Niagara, with about 5 per cent of cases linked to travel to or from the Greater Toronto Area, where most of Ontario’s COVID-19 infections are. He emphasizes that’s probably just “the tip of the iceberg,” since asymptomatic carriers can spread the virus undetected, and contact tracing cannot always determine a person who qualifies having close or prolonged contact with a positive case.

“Two weeks after the lockdown in Peel and Toronto, we saw a big spike in cases here in Niagara. Usually it’s about a two-week lag between an intervention and seeing the impact of COVID-19 spread. I think that’s a hint that travel probably had an impact there,” says Hirji.

Hirji says public health has not definitively established that link. One of the challenges is that even if contact tracing shows someone was at a mall, for example, there’s not always a way to show whether they were in close contact with anyone from another part of the province. What’s more, rising case counts in Niagara have overwhelmed public health’s capacity to do contract tracing as effectively as it would like, he says.

In the lead up to the holidays, travel for shopping has been a concern in areas within driving distance of the GTA. The severity of traveller spread came to the forefront in Hamilton last week, when a local mall extended its hours in an attempt to accommodate increased traffic from out-of-town shoppers. Residents and local officials criticized the decision, saying they worried it would encourage shoppers to come from areas with more COVID-19 transmission, thereby driving up cases in Hamilton.

In Halton, storeowners have reported high traffic, some of which they attribute to people from neighbouring regions where non-essential stores are closed. Halton’s medical officer of health,  Dr. Hamidah Meghani, released a statement Monday “instructing retailers to control crowding and enforce physical distancing and capacity limits within their establishments.

In a series of studies on GTA travel behaviour in the spring, University of Toronto professor Khandker Nurul Habib and his colleagues found most people in the area reduced their daily travel activities during the initial wave of pandemic infections and restrictions by about 50 per cent. They also found people who were making trips were making them later in the day and longer in distance.

Nurul Habib says there are a couple possible reasons. “People wanted to go out of Toronto, where COVID was not as severe,” he posits. Another possible reason for increased travel distance is that less traffic on the roads meant people could go farther than usual in less time. “If you lift constraints, people will make more trips,” he says.

While Nurul Habib hasn’t yet been able to study travel behaviour during the pandemic’s second wave, a recent report from the Toronto Star included analysis of cell phone location data in the GTA, which showed people have not significantly limited their travel since tighter restrictions began in November. While experts told the Star many people were likely travelling for essential reasons such as work, data also showed people travelling out of the city, seemingly to shop in places with fewer restrictions.

“The ability to cut off travel has such a big impact on the ability to control the spread of COVID-19” says Hirji, citing the success of island countries, such as Taiwan, Singapore, New Zealand, Australia, and South Korea, in controlling viral spread.

He also notes that overall, social activities are the major driver of spread in Niagara, whether linked to travel or not. Public health staff report about 68 per cent of Niagara’s COVID-19 cases have been linked to close contact with others, and about 21 per cent to community spread. Hirji says people who know one another are more likely to be lax with COVID-19 prevention measures and stay together for long periods of time, upping the risk of exposure.

The same has been true in Hamilton, where public health staff report about 3 per cent of cases in the city have been linked to travel (they did not specify a figure for travel within Ontario), with 40 per cent due to close contact and 25 per cent community-acquired.

TVO.org requested an interview with Hamilton’s medical officer of health but was not granted one. In an emailed statement, Hamilton public health said it is recommending residents “avoid non-essential travel, especially from higher-transmission to lower-transmission areas.”

Since Monday, restrictions in Hamilton have prohibited gathering indoors with anyone not already living in one’s own household (except for people living alone, who can join another household). Come December 26, the same will be true across Ontario, but until then, public gatherings and social events in Niagara are limited to 10 people indoors and 25 people outdoors, provided proper safety precautions are taken.

Along with the medical officers medical officers of health in Toronto, Peel, Halton, Hamilton, Windsor-Essex County, and Waterloo, Hirji signed a statement released Sunday recommending all social gatherings — even outdoors — be avoided during the holidays. “That’s the only way we’re going to avoid a big spike of infections,” he says.

While large events in Niagara seem to occur less frequent now than before, Hirji says he thinks the public has been unwilling to curtail socializing “to the extent we need to keep COVID-19 under control.”

That can have life-threatening consequences. Hirji cites a recent case in Niagara in which a group of extended family members from different cities got together. “Unfortunately, one of the individuals there had COVID-19. It spread to most members of the family at that gathering. And, unfortunately, two individuals, at least, ended up on ventilators due to the infections.”