BOSTON — A large swath of the Merrimack Valley was cloaked in “red” Wednesday as the number of communities at high risk for COVID-19 infections spiked over the past week.

The Department of Public Health reported 23 communities are coded “red” —including Lawrence, Lynn, Methuen, Haverhill and North Andover — meaning they had an average of more than 8 daily coronavirus cases per 100,000 residents over the last 14 days, once numbers are adjusted for population. That’s up from 15 communities the previous week.

North Andover skyrocketed to the state’s highest COVID-19 infection rate — or 26.2 infected per 100,000 people — after reporting a spike of 111 cases in the past 14 days.

Merrimack College, which is based in North Andover, temporarily moved to remote classes this week following an outbreak in a student dormitory. More than 60 students and staff had tested positive for the virus as of last Friday, according to the school.

Boston also jumped into the high-risk “red” category in the past week, according to the latest health report, with 8.5 per 100,000 cases.

Eighty municipalities were coded yellow, a moderate-risk category of between 4 and 8 cases per 100,000, in the state’s weekly report.

Another 59 communities were shaded in green, meaning an average daily COVID-19 infection rate of less than 4 cases per 100,000 residents.

Locally, Haverhill, Methuen and Middleton moved from yellow to red after reporting spikes in coronavirus cases, according to the DPH report.

Other Merrimack Valley communities such as Dracut and Lowell were also listed as “red” high-risk categories as well.

As of Wednesday, Lawrence’s COVID-19 infection rate was 25.4 cases for every 100,000 people, the second-highest rate in the state.

In Haverhill, Mayor James Fiorentini said he has asked the Board of Health to hold an emergency meeting on Thursday where he plans to request temporary emergency measures.

He said he will ask the board to adopt a rule that requires restaurants to keep contact names and phone numbers to aid in contact tracing efforts. He’ll also ask the board to strengthen the city’s mask ordinance to require people to wear masks at all times in the downtown district unless they are at a table eating.

“I will be working with the school superintendent and our recreation department and taking a look at whether we need to place school and recreation sports on hold for a couple of weeks until these numbers go down,” the mayor said.

Methuen shared via Twitter that the city moved into the high risk category after recording 62 new cases of COVID-19 from September 22 to 29. The post also noted that Methuen would be adding a link to the city website where residents could report “any COVID-19 violations.”

Across the state, the majority of cities and towns are coded white, which indicates fewer than five total cases.

Still, Essex County has the second highest infection rate of any region in the state, with an average of 9.2 cases per 100,000 residents over the past two weeks. The state’s average rate is 5.7.

Gov. Charlie Baker said most cities and towns have COVID-19 transmission rates low enough to lift restrictions on some businesses and allow schools to reopen for in-person learning.

The state reported 510 new coronavirus cases Tuesday and 32 deaths. There have now been 9,242 COVID-19-related deaths and 129,753 cases since the outbreak began in March, according to state health officials.

Baker said the state goal of the weekly listing is to direct aid to help high-risk communities battle the virus and enforce reopening rules.

Cities and towns at moderate- or high-risk have been offered state assistance with testing, contact tracing, enforcement and public awareness campaigns.

For more information: www.mass.gov/stopcovid19

Christian M. Wade covers the Massachusetts Statehouse for North of Boston Media Group’s newspapers and websites. Email him at cwade@cnhi.com. Eagle-Tribune reporter Mike LaBella contributed to this story.

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