As the Covid-19 vaccine makes its way to front-line medical workers, Dartmouth is showing a slight decline in cases this week — likely due to a drop in testing, according to Public Health Director Chris Michaud.

Board of Health data released on Dec. 18 shows 157 new cases this week, down from 177 the week before.

No residents have died from the virus in the past seven days — although there have been 55 virus-related deaths since the start of the pandemic.

According to Michaud, who spoke at an emergency School Committee meeting on Dec. 15, the decline is due to a drop in testing, including a recent shift to appointment-only tests at a large New Bedford drive-thru site.

State data from Dec. 17 shows the town’s 14-day percent positivity climb to 7.94% — up from 6.9% last week — and the average daily incidence rate climb from 51.2 to 63.7 per 100,000 people.

Michaud warned officials at the emergency meeting that the town continues to see widespread community transmission of the virus, urging the public not to take an apparent decline in cases as “reason to relax.”

“I don’t think those numbers are going to be representative of transmission in Dartmouth,” Michaud said. 

He pointed to the near-doubling of the state’s number of Covid infections in the first week of December due to the Thanksgiving surge, noting that Christmas is coming up.

Businesses are now required to call the health department every time an employee tests positive. “The number of calls coming in over the last seven to nine business days has been unprecedented,” he said. “This is a barometer of what is truly going on in the community.”

Town data also shows 77 active cases among students and staff at Dartmouth’s public schools, with the illness affecting more than 2% of students in the system.

Across all six schools, 65 students and 12 employees are currently positive for the virus, with 52 cases already resolved — meaning the person has completed the required 10-day isolation and can safely return to in-person learning.

Dartmouth High School is the most affected school, with 27 students (or 2.9% of the student body) and four staff members actively infected and isolating.

At the emergency meeting, the School Committee discussed the option to return to fully remote learning after the winter break. 

It will likely make a decision on the issue at the next committee meeting on Dec. 21.

Dartmouth — along with the rest of the commonwealth — had to take a step back in the state’s four phased reopening plan earlier this month after remaining in the “high risk” category for three straight weeks.

Michaud has stressed that residents should take all necessary precautions to reduce the risk of transmission, reminding them that just 15 minutes of contact accumulated over 24 hours can transmit the virus.

Meanwhile UMass Dartmouth reports nine new positive Covid cases in just two days, Dec. 14 and 15, the latest for which data is available.

As of Dec. 18, Massachusetts has 80,989 estimated active Covid-19 cases, with 11,358 confirmed coronavirus-related deaths reported. There have been 28,515 cases in Bristol County since the start of the pandemic.