Study narrows which seats on a train put you most at risk of COVID-19

A recently published study shows that where and how long you sit on a commuter train could impact your chances of contracting COVID-19.

In a study conducted by a number of Chinese institutions and the University of Southampton in the UK, researchers determined that there was “high transmission risk” of the infectious virus amongst those who took transit. Passengers who sat directly beside someone with the virus were placed in the highest risk.

Researchers examined data made available by Chinese health authorities, along with rail timetables of China’s G trains between the middle of December and late February. The G train is considered to be the country’s busiest train.

They were able to identify 2,334 “index patients,” passengers who began exhibiting symptoms of COVID-19 within 14 days of riding the train and were eventually diagnosed with the virus. They also reviewed 72,093 other commuters who sat within three rows and five seats of those key patients.

The study found that 234 of the 72,093 passengers who sat near an index patient — 0.32 per cent — ended up contracting the disease, a number the study calls the “attack rate.”

The attack rate for passengers who sat in the same row as the patient was 1.5 per cent, which worked out to 10 times the rate compared to those seated in front of the patient or further behind. The attack rate was 3.5 per cent for commuters seated next to the patient. It didn’t seem to matter whether the index patient sat in the aisle, middle or window seat, though researchers suspect those sitting in the same row were likely to get infected as a result of the lack of barrier, such as headrests.

The study found that the attack rate went up by 0.15 per cent per hour of travel time, and 1.3 per cent per hour for commuters seated directly next to the patient.

Isaac Bogoch, an epidemiologist at the University of Toronto, says the study confirms what many leaders in infectious disease in public health have been saying for a while.

“The overall risk on public transportation is lower than what many people think but of course it’s not zero per cent,” he tells Yahoo Canada. “The key variables for acquiring this infection is proximity to an infected individual and the duration of time you’re in close proximity to an infected individual.”

He adds that if people put on a mask, are able to spread out and practice hand hygiene, the risk of catching this infection on public transport is low.

In an email to Yahoo Canada, David White, a family doctor at North York General Hospital, provided several other transportation options that would be considered a safer way to travel:

• In your own vehicle — no mask required if all passengers are in the same bubble.

• Walk or cycle — wear a mask if you’re unable to maintain two metre distancing

• As a passenger in another driver's vehicle, sitting in the back with a window open with everyone in the car in masks (if they are not all in the same bubble)

• Public transit during off-peak times when spacing is possible, everyone is in masks, using hand hygiene before doffing the mask, and avoiding touching one’s face