Health officials in New Jersey are advising nearly 3,000 people to get blood tests after an outbreak of hepatitis B in Ocean County.

Five people — all of whom have the same doctor — recently were found to have the disease, which can affect the liver and become chronic if untreated. The doctor's other patients were advised to get blood tests.

Investigators aren't sure what caused the outbreak. Ocean County health officials say two cases of hepatitis B were confirmed there in late February, and state officials recently learned of three more cases, all in Toms River.

Robert Conroy, the lawyer for Dr. Parvez Dara, who has offices in Toms River and Manchester, says his client isn't responsible for the outbreak.

Heptatitis B is transmitted through exposure to infectious blood.