New Jersey officials said Wednesday that 43 staff and students have been infected with the coronavirus at school since returning to classrooms this month, with seven of the 11 schools affected located in South Jersey.

Three schools in Cape May County, two in Burlington County, and two in Gloucester County have reported cases of in-school transmission. Officials did not identify the schools but said anyone connected with an affected school is notified before the cases are reported publicly. They did not say any of the 11 schools statewide had closed.

With about 3,000 schools open for some in-person learning, according to the interim state education commissioner, the outbreaks have affected a very small fraction of students.

Gov. Phil Murphy said the scope of in-school infections so far is “probably as good as I would have hoped … but the last thing we want to do is pat ourselves on the back and wake up the next day and find that number went up by multiples. But I would say as objectively as I can, it’s a pretty darn good result.”

The Pennsylvania Department of Health remains most concerned about college students, Secretary Rachel Levine said Wednesday, and is working with Pennsylvania State University in particular to try to decrease the number of new cases there.

Since some Penn State students returned to the State College campus in August, the university has reported 2,475 cases, 701 of which were active as of Monday, the last time the school’s virus dashboard was updated.

Pennsylvania on Wednesday reported 1,153 newly confirmed cases and 19 additional deaths. Philadelphia reported 141 new coronavirus cases and 10 newly identified deaths; the city’s seven-day average sat at three deaths per day.

Cases were increasing in Pennsylvania, New Jersey, and Delaware. On Wednesday, Pennsylvania’s average number of new cases per day was about 38% higher than one month ago; New Jersey’s was 92% higher; and Delaware’s was 66% higher, according to an Inquirer data analysis.

Reporting 722 new cases, New Jersey officials said 188 of those are in Ocean County, where an outbreak is growing.

Nearly all those cases were reported in Lakewood, known for its large Orthodox Jewish population. While the state’s positivity rate is 3%, it is 27% in Lakewood, meaning more than a quarter of tests taken there have been positive, said Health Commissioner Judith Persichilli.

Health officials have sent additional contact tracers to Ocean County and will be visiting this week to meet with community leaders and assess the situation.

“This is something we are taking very, very seriously,” Murphy said. “We’re all trying to figure out the Ocean County spike.”

The cases in schools were announced as New Jersey launched an online dashboard on the state’s main COVID-19 page to track school outbreaks. An outbreak is defined as when two or more students or staff in a school become sick within the same two-week period.

Schools with two cases from the same classroom can remain open, Persichilli said, provided that contacts of those who were infected stay home for two weeks. If multiple staff members, students, and families served by one school become sick, local health officials can recommend the school be closed for two weeks.

As of the start of the school year, 434 school districts were using a hybrid teaching model and 68 were offering full-time in-person instruction. The rest, 242, were remote only.

Kevin Dehmer, interim commissioner of education, said some schools are still having problems getting electronic devices, and state officials are still working to get all students access to classes online. The state will also soon distribute 2.4 million masks from the U.S. Department of Health and Human Services to schools.

“We’re re-creating an entirely new delivery system of public education,” he said.

Staff writers Erin McCarthy and Rob Tornoe contributed to this article.