There are now 328 total coronavirus cases in Massachusetts, up 72 from a day earlier.
It's the largest spike since the number of cases jumped from 41 to 92 back on March 10, the same day Gov. Charlie Baker declared a state of emergency.
Massachusetts is one of the states in the U.S. with the most coronavirus cases in the country so far. While no one has died from the virus locally, more than 150 people have died nationwide, two of them in Connecticut.
In-depth news coverage of the Greater Boston Area.
Severe restrictions to daily life have been ordered in Massachusetts, including school cancellations, restaurant closures and limits to gathering in groups, as the state fights to mitigate the spread of the deadly pandemic.
Over 2,000 Massachusetts residents have been quarantined due to coronavirus, health officials said earlier this week.
Baker said Wednesday that Massachusetts expects to see an "enormous increase" in its coronavirus testing capabilities in the next several days and weeks.
For days, the majority of Massachusetts' cases accounted for in the Department of Public Health's numbers were related to an employee meeting held by local biotech company Biogen at a downtown Boston hotel. But that is no longer the case -- Thursday's figures report 97 people tied to the meeting directly or through members of their household.
Forty-six cases have been found to be transmitted locally and 34 are travel related, according to the numbers. Another 151 remain under investigation.
Someone now has the coronavirus in at least 12 of the state's 14 counties.
One hundred and nineteen of the state's cases are in Middlesex County, 72 in Suffolk, 52 in Norfolk, 18 in Berkshire, 19 in Essex, 14 in Worcester, six in Bristol, five each in Barnstable and Plymouth, three in Hampden and one apiece in Franklin and Hampshire. Thirteen other cases haven't yet been traced to a specific location.
Forty-three cases so far have been confirmed as needing hospitalization, while 125 remain under investigation and 160 people haven't needed to go to the hospital at all.