SOMERVILLE, N.J. (CBSNewYork) — Infectious disease experts are concerned about skyrocketing hepatitis A infections in New Jersey.

CBSN New York’s Meg Baker found out more Wednesday about the recent outbreak.

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Just this week, patrons of a ShopRite in Somerville were being warned to toss any lunch meat or other items they picked up from the deli counter late last month, after an employee was diagnosed with hepatitis A.

“I buy lunch meat here all the time. I know I’m in that group that bought it. We ate it,” customer Paul Cichello said.

Hepatitis vaccine (credit: Robyn Beck/AFP/Getty Images)

The disease is spread when someone with hepatitis A uses the bathroom, does not wash their hands properly and then touches food that someone else is going to eat.

The New Jersey Department of Health said there have been 541 confirmed cases statewide since Dec. 1, 2018. That’s a steep increase from last year’s 67 cases.

In addition, 337 people have been hospitalized with hep A, and six have died in 2019, including a member of Mendham Golf Club, who was infected by a food handler.

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Hepatitis A symptoms include: fever, diarrhea, stomach pain, poor appetite, vomiting, and yellow skin/eyes.

So what’s causing the outbreak? The state said the increase is among persons reporting homelessness, drug use, and those who have recently been incarcerated.

Contagious disease experts said a vaccine that can prevent hepatitis A is 95% effective and lasts about 11 years.

The Somerset County Department of Health will host a special walk-in clinic to provide free hepatitis A vaccinations. It will be held at the county Human Services building on Warren Street in Somerville on Wednesday and Thursday from noon to 8 p.m.

For more information, call the Somerset County Department of Health hepatitis A hotline at 908-203-6014. For directions, click here.

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We’ll have more on this story on the CBS2 News at 5 p.m.