Far more Massachusetts residents may have contracted the novel coronavirus than state data suggests, according to British researchers.
In a study by the Imperial College London, the researchers estimate that 13-percent of the state's 6.9 million population -- some 897,000 people -- has contracted the disease. That's sharply higher than the 93,271 reported by the state as of Monday.
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The researchers said its model took into account publicly available data as well as mobility data from companies such as Google.
According to the study, some 96,000 were infectious with COVID-19 as of May 17, trailing only Illinois.
The estimates come as the state moves to cautiously reopen its economy through a phased-in approach, despite concerns opening too quickly could cause a second wave of COVID-19. Researchers fear the virus could end up returning, more than doubling the current death toll nationwide.
Last week, Massachusetts allowed construction and manufacturing, as well as worship services, to resume with restrictions.
On Monday, the state allowed more businesses to resume some in-person activities, including hair salons and pet groomers. Beaches and parks opened as well, with restrictions.
Officials will be watching key public health metrics to determine if and when it is appropriate to proceed through reopening phases, including the coronavirus positive test rate, the number of deaths and hospitalizations, testing and tracing capabilities and the capacity of the health care system.
Each phase will last at least three weeks and could last longer, contingent on state data. If health data trends are negative, specific industries, regions or the entire state may need to return to an earlier phase.