By Matt Petrillo

OCEAN CITY, N.J. (CBS) — State officials in New Jersey and Pennsylvania are worried about COVID-19 spreading from gatherings down the shore. Shore rentals have become a concern because families and friends are again renting big homes together, like in Ocean City.

Nick Cassa, of Pottstown, Montgomery County, rented a house in Ocean City with friends from Reading, Berks County. They’re not too worried about contracting COVID during their stay.

“If you’re within six feet of somebody, you have to wear a mask and pretty much everybody abides that,” Cassa said.

Eyewitness News found many friends who don’t live together but are sharing a place down the shore.

“I don’t see it as an issue for myself,” one vacationer said. “You lock up people for three months, they’re gonna need a vacation.”

For Ocean City’s Berger Realty, shore rentals took a big hit in May and part of June. But July shore rentals are back to where they were this time last year.

“We checked in company-wide, probably close to 1,200 families this weekend,” realtor Frank Shoemaker said.

Homes are being sanitized and many people are trying to wear masks and keep a distance from each other.

But people traveling down the shore being in close contact with friends or family who they don’t live with is a cause for concern to health officials.

Data shows COVID-19 cases are climbing in Philadelphia and its suburbs faster than any other part of the state.

“When we asked where you think you were exposed and what you’ve done during the time period when you think you were exposed, travel to the beach comes up pretty frequently and that makes us concerned. So our recommendation, based on that, is for people to avoid the shore,” Philadelphia Health Commissioner Dr. Thomas Farley said.

Farley also says it’s not the ocean that’s the risk but he says traveling in the same car and staying in the same place with those who you don’t live with may expose you to COVID-19.

Data also shows Delaware County is leading the state with COVID-19 cases by population. It stands about 13 per 100,000 people per day over the last week.