BOSTON (WHDH) - Six counties in Massachusetts are now considered high-risk for COVID-19 transmission, while seven others are at substantial risk, according to the Centers for Disease Control and Prevention.

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The latest data from the CDC shows Berkshire, Hampden, Suffolk, Bristol, Dukes, and Nantucket counties have a high COVID transmission rate, with more than 100 new cases reported per 100,000 residents between Aug. 2 and Aug. 8.

Franklin, Worcester, Middlesex, Essex, Norfolk, Plymouth, and Barnstable counties all have substantial transmission rates, with between 50 and 99.99 new cases reported per 100,000 residents in that same seven-day period.

Hampshire County has a moderate transmission rate, meaning there have been between 10 and 49.99 new cases reported per 100,000 residents in the last seven days.

The CDC now recommends that vaccinated people return to wearing masks indoors in every Massachusetts county that is at high or substantial risk because the COVID-19 Delta variant is fueling a surge in new cases.

Bay State health officials on Monday reported 2,587 new COVID-19 cases, three additional deaths, and a seven-day positivity rate of 2.72 percent.

Since the state began tracking coronavirus metrics, there have been 681,131 total confirmed COVID-19 cases and 17,730 deaths.

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