Mass. reports 229 new coronavirus cases, 16 new deaths; UMass model predicts 8,389 total deaths in 4 weeks

A COVID-19 drive-thru testing center in Lawrence.John Tlumacki/Globe Staff/file

State officials reported Tuesday that the coronavirus death toll in Massachusetts had risen by 16 to 7,890 and that the number of people testing positive for the virus had climbed by 229 to 107,439, as key metrics monitored by the state lingered at low levels relative to the springtime surge.

The numbers reflected both confirmed and probable deaths and cases. When confirmed cases only are included, the tally is 7,710 deaths and 102,651 cases.

The state reported 16 new confirmed-case deaths, and no new probable deaths. It also reported 182 new confirmed cases, plus 47 probable cases.

The state also reported that 7,532 new individuals had been given the molecular coronavirus test, bringing the total of individuals tested to 782,854. The total number of molecular tests that have been administered rose to 985,711.

The state also reported that new antibody tests had also been completed for 721 people, bringing that total to 65,313.

Meanwhile, three of the four key metrics that the state is monitoring to determine the pace of reopening fell, while one ticked up slightly.

The seven-day weighted average of positive test rates dropped slightly to 1.9 percent on Monday, down from 2 percent on Sunday. It has dropped 93 percent since April 15.

The three-day average of the number of patients hospitalized for the coronavirus decreased on Monday to 933 from 937 a day earlier. It has dropped 74 percent since April 15.

The number of hospitals using surge capacity ticked up slightly from two on Sunday to three on Monday — a statistic that is still down from a high of 21 in early May and that has seen an 86 percent decrease since April 15.

Meanwhile, a fourth metric, the three-day average of COVID-19 deaths, fell slightly from 26 on Friday to 20 on Saturday. That number has also dropped 87 percent since April 15.

The numbers were released after a University of Massachusetts model estimated that the coronavirus death toll in the state will reach 8,389 by July 18.

The UMass estimate comes from a lab headed by UMass Amherst associate professor Nicholas Reich that collects various coronavirus pandemic models and develops a combined, or ensemble, forecast that is intended to reflect their collective wisdom.

Reich’s lab releases the ensemble forecast weekly. It only creates the forecast for a four-week window ahead because it believes forecasts aren’t reliable enough after that. Last week, the model estimated there would be 8,309 deaths tallied by July 11.

Reich’s lab posts its national- and state-level data at the Reich Lab COVID-19 Forecast Hub. The lab, already an Influenza Forecasting Center of Excellence, collaborates with the US Centers for Disease Control and Prevention on coronavirus predictions.

The lab also feeds the data it has collected and its ensemble forecast to the agency, which posts the data on its own website. The data is also used to feed the fivethirtyeight.com website.

The closely-watched University of Washington Institute for Health Metrics and Evaluation model, looking further into the future, predicts Massachusetts will see 8,671 deaths by Oct. 1.

The latest UMass ensemble model also predicts the United States as a whole will see a cumulative total of 139,276 deaths in four weeks. Last week it put the four-week number at 135,461. The current US death toll is over 120,000, according to Johns Hopkins University.

Concerns are being raised about surges of cases in the South and West that may soon be followed by a surge in deaths.