Boston Mayor Marty Walsh said Wednesday that the citywide positive test rate for COVID-19 has risen significantly, for the second week a row, to roughly 3.5 percent from about 2 percent or less earlier this month.

The latest statistics for Boston reflect rising COVID-19 infection rates, albeit at lower levels overall, across Massachusetts, as the state proceeds with a phased re-opening plan.

Walsh said as many as half of new infections citywide are among the city’s Latino communities; and that roughly half of those infected have been under the age of 29 — a population that includes college students returning to Boston campuses.

The numbers, Walsh said, mean that Boston is at or approaching the “red” category of Massachusetts municipalities with higher COVID-19 infection rates.

“We expect to be in the Red Zone very soon, and it’s likely to happen this evening,” Walsh said.

Walsh expressed dismay and audible frustration with college and university students, saying that pockets of COVID-19 outbreaks have been linked to small groups of higher education students who have engaged in “irresponsible” behavior.

“This is a serious virus,” Walsh said. “If you’re 21, if you’re 19 and you get COVID, yeah – the numbers say you’ll probably be ok.”

“But what the numbers don’t say is your parents won’t be OK. Your grandparents won’t be OK. Your elderly neighbor won’t be OK," he added. "So we’re asking people to act responsibly.”

“I’ve watched, in the last seven months here, what it means to close the economy,” Walsh said, ”I’ve watched what it means [to] all the people who have lost their job. I’ve watched what it means to the people who can’t pay their mortgage.”

“We are better than that. And we have to start acting better than that.”

The overall increase in infections, Walsh said, has manifested in most Boston neighborhoods, but with several neighborhoods remaining well below the higher citywide infection rate, including Jamaica Plain, Roxbury, the South End, Back Bay and Fenway, and Charlestown.

Despite the recent rise in COVID-19 cases, Walsh said Boston Public Schools is proceeding for now with plans, laid out this summer, to let students opt in to in-classroom learning on a part-time basis and in phases over the coming months.

Walsh has set a threshold of a citywide positive test rate of 4% as a trigger to suspend in-classrom learning.
Wednesday's 3.5% citywide positive test rate, while close to that threshhold, remained below it, Walsh said, and in-classroom learning will begin for students with special needs Thursday as long as that remains the case.

According to the plan, other groups of students will be given the option of returning to classrooms part-time over the course of this fall.

All Boston public schools, the mayor said, are ready for in-classroom learning.

Walsh said the city will not be moving forward with certain re-opening measures under the state’s “Phase 3” reopening plan, meaning various indoor activities will remain closed, including indoor performances. Other businesses will remain at limited capacity.