BOSTON — Massachusetts is in the early phase of opening back up, but already one COVID-19 forecasting model is hinting at trouble.
The model, developed by MIT graduate Youyang Gu, is one of the few to incorporate state reopenings as a factor in predicting future infections with the novel coronavirus. And this week, covid19-projections.com showed a slight uptick in the Rt or R0 for Massachusetts -- a measure of the virus's likelihood of spreading.
On May 18, 2020, when the state began the reopening process, the R0 stood at .89. On June 3 it moved up to .92, a level not seen since April 14, 2020.
"Once it hits just above one, that's when we start to see true epidemic growth again," said Dr. Brooke Nichols, a mathematical modeler and health economist at Boston University's School of Public Health. "It's worrying. Because we have in Boston, in Massachusetts really small opening up and we do see that increase in Rt. And I do think that once we get back on the T and people start commuting for work again and gathering that we might see that increase above one."
The model shows that happening already in states that reopened earlier and more aggressively than Massachusetts, most notably Georgia.
“Since they opened up they’ve seen their reproductive number, their Rt, go above one,” Dr. Nichols said. “And then you can see that directly affect the expected number of active cases over the coming months.”
Georgia’s R0 rose above 1 on May 3, 2020, and now stands at 1.07, according to the model, which also projects infections to steadily rise there until at least early July.
By contrast, the model projects infection numbers will fall in Massachusetts through the summer. But by the end of August that could still mean some 20,000 active cases, most of those likely undiagnosed, said Youyang Gu, who talked with Boston 25 News by phone from California.
In fact, the model assumes the number of COVID-19 infections, overall, has been vastly underestimated, in most regions by a factor of 5 to even 15.
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The Department of Public Health reports the official number of infections in Massachusetts is closing in on 101,000. But including never-diagnosed infections, Gu's model puts the number between 600,000 and 1.18 million infections since the pandemic began in Massachusetts.
Dr. Nichols agrees the 'official' counts are off.
"All the evidence does suggest that we are indeed. The case number that's reported is a sore underestimate of the true number of people who have been infected," she said.
If the R0 does climb above one, Dr. Nichols expects the state would take measures to pull it back down, something successfully done last March.
Will the recent protests boost infection numbers? Gu said it's hard to say.
In some cases demonstrators have interrupted 'reopening' plans, he said, thus cutting out that risk of infection. So any increase from the protests may not be obvious.
But some residents said they are basically just waiting for the COVID-19 numbers to rise.
"All the people out protesting, understandably, are not following social distancing and that's very concerning in healthcare that we're going to continue having an upsurge when people don't follow the rules," said a nurse from Franklin. "I have a feeling we're going to see an up-rise in patients, and that's very concerning."
“I think that since we’ve started to open up people have gotten more haphazard about it,” added a Medway resident. “Some of them have masks, some of them don’t. Some of them are six feet apart. I mean obviously it’s going to go up from here.”