Pittsburgh ? The number of people infected in a hepatitis A outbreak linked to a western Pennsylvania restaurant has exceeded 500 and is likely to continue rising for another week, state Health Department officials said Saturday.

Three people infected with the virus have died, and thousands have lined up for inoculations since the outbreak was reported in early November among people who ate at a Chi-Chi’s Mexican restaurant.

As of Saturday, 510 cases of hepatitis A had been confirmed in the outbreak, Pennsylvania Health Department spokesman Richard McGarvey said.

He said more infections were expected because people who contracted hepatitis A typically didn’t exhibit its early flu-like symptoms for 28 to 30 days.

The state started offering antibody inoculations Nov. 5, shortly after the first cases were diagnosed, to anyone who ate at the restaurant after Oct. 22. The antibody greatly reduces the risk of hepatitis A developing, but it must be given within two weeks of exposure.

The virus’ nearly monthlong incubation period means people exposed before Oct. 22 could still start showing symptoms through next weekend. In severe cases, it can lead to liver failure.

“We still haven’t reached that date, when all those inoculations are going to help,” McGarvey said Saturday.

About 8,500 people received the shots because of the outbreak linked to a Chi-Chi’s at the Beaver Valley Mall, about 25 miles northwest of Pittsburgh.

Health investigators say they still don’t know the source of the virus. They’re looking at green onions, which are difficult to clean and have been linked to smaller outbreaks in other states.