New Jersey is facing a particularly intense hepatitis A virus (HAV) outbreak this year, with six people dead and more than 500 cases so far, according to recent statistics released by the New Jersey Department of Health (NJDOH).

Officials are now warning residents about the outbreak, noting that 308 people so far have been hospitalized across 21 New Jersey counties, including the state’s popular Jersey Shore communities, Jersey Shore Online reports.

New Jersey’s outbreak demonstrates a significant increase in new infections since last year, which saw 64 reported hepatitis A infections overall. According to the NJDOH, a recent case of hepatitis A involved a food handler in Paterson, New Jersey. Officials say those who went to Brother’s Produce between September 30 and October 5 may want to get tested for the virus. 

Hepatitis A is transmitted through contaminated food and water as well as via close person-to-person contact. Several outbreaks have made their way across the United States over the past few years. People who are experiencing homelessness, people who use drugs, and men who have sex with men (MSM) have been at the most risk for infection—though food-related outbreaks also regularly expose people to infection. 

Hepatitis A can be prevented with a simple vaccine. Those who haven’t yet gotten one (mainly people born before the ’90s) can ask their doctors or local health department for a protective shot.

To learn more about hepatitis A, click here.