TRENTON, N.J. (CBS/AP) — New Jersey’s top health official is warning of a “second wave” as the state added 1,300 new positive coronavirus cases overnight, over 1.5 times more than the previous day’s figure — and the highest level since late May. The biggest increases are in Ocean and Monmouth Counties.

Health Commissioner Judy Persichilli said most of the positive cases in Ocean County stem from Lakewood, predominantly among white men ages 19-49 and could be related to religious services or celebrations that occurred in late September.

Hospitalizations also climbed to 652, the highest level since early August, Gov. Phil Murphy said.

Eleven people were reported to have died overnight, bringing the statewide total to 14,373. The positivity rate for testing stood at 3.69%, while the rate of transmission fell to 1.22, down from 1.27.

The uptick in cases and hospitalizations could mean a return outbreak.

“We are anticipating a second wave, and we are preparing based on our prior experiences,” Persichilli said. ”This wave has a potential to become a surge.”

The state has stockpiled personal protective equipment, ventilators and the therapeutic drug remdesivir. She said the biggest concern will be staffing because other states sent health workers in March and April, but those people are confronting the outbreak in their on states now.

She didn’t give a time frame for when the wave could hit.

For most people, the virus causes mild or moderate symptoms. Older adults and people with existing health problems are at higher risk of more severe illness or death.

(© Copyright 2020 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)