The number of COVID-19 hospitalizations in New Brunswick could double within a month if contact rates don't dramatically drop, new provincial modelling shows.
Contact rate refers to the number of people an average person interacts with on a given day, times their chance of getting infected per contact, said Sanjeev Seahra, professor and chair of the University of New Brunswick's department of mathematics and statistics in Fredericton, who worked on the projections with the Department of Health.
People have roughly a 4.5 per cent chance of getting infected when they have contact with a person, he said.
So seeing fewer people reduces their contact rate.
Other measures can also help, such as reducing the duration of contact, physical distancing and wearing a mask, said Seahra, who is also director of the Atlantic Association of Research in the Mathematical Sciences.
If nothing changes, hospitalizations could hit 120 by early November, according to a graph compiled this week and released by the department. No other accompanying data was provided.
If New Brunwickers reduce their contact rate by 20 per cent, that number would peak at 70 within a couple of weeks, according to the graph.
"It shows that reducing the contact rate between individuals and reducing the number of contacts you have and limiting yourself to the most essential contacts really does have a big, big effect on what's going on in the hospitals in the province, for sure," said Seahra.
As of Saturday, 56 people were in hospital because of the virus, with 23 in intensive care.
Although reducing the contact rate doesn't depend only on seeing fewer people, if you usually see 10 people on a given day, a 20 per cent reduction would mean that you see only eight of them.
That's an average, Seahra said. We have longer and "more intense" contact with family members, for example, compared to co-workers, or strangers at the mall.
"If you cut out your contact with one of your family members, that would have a huge effect. Like, it might be more than 20 or 40 per cent," he said, whereas cutting out someone you have casual contact with a work for a few minutes each day would have "a lesser effect."
Asked whether the province's mandatory order, which was reinstated on Sept. 24 and requires people to limit their contacts to their household plus their "steady 20," which includes family and friends, has already been factored in, Seahra said the order is relatively new and reducing contact rates looks at longer-term averages.
"I think the most appropriate thing would be to, you know, take the pessimistic view, is reduce it from 20 per cent as of today," he said. "I think that's the most reasonable thing to do."
The government has limited private Thanksgiving gatherings this long weekend to single households, plus any one additional person who lives alone at another address and requires support, and introduced a two-week circuit breaker for parts of Zones 1, 2, 3, 5 and all of Zone 4.
But it has made no request that people cut their contacts by any percentage.
A 40 per cent reduction in the contact rate is predicted to have a "pretty significant and quick effect on the increase in the number of hospitalizations, causing it to level off within a week or two timeframe," said Seahra. By Christmas, there would be no hospitalized COVID patients, the graph shows.
A 60 per cent decrease would result in "a more pronounced drop in the number of hospitalizations in the future," down to about 20 by the end of the month, the modelling indicates.
"Everything would help," said Seahra, whether it's someone choosing to work from home, if they're able, or making fewer trips to the store.
Previous modelling released by the department earlier this week had predicted up to 64 people could be hospitalized as of Friday.
"The high scenario would represent 56 to 64 beds occupied by October 8th," department spokesperson Bruce Macfarlane said Monday.
The department did not respond to a request to release projections for ICU admissions, new cases or deaths.
Seahra said he has done some modelling for ICU admissions, "but they're harder to predict for various reasons."
"That's kind of work in progress, so I can't say anything very definitive about that right now."
He deferred inquiries about new cases and deaths back to the department.