Hepatitis A outbreaks in restaurants often cause anywhere from 25 to 200 cases, according to the Centers for Disease Control and Prevention. An outbreak at a Missouri eatery in 1990 sickened 110 people. A short while later, 230 people came down with hepatitis A in an outbreak involving two sandwich shops in Milwaukee.
But state officials said yesterday the number sickened from an outbreak at the Chi-Chi's restaurant in the Beaver Valley Mall could continue to grow as lab reports come in this week.
The state Department of Health yesterday closed its hepatitis clinic at the Beaver County Community College. In five days of operation, 8,884 people were screened for exposure to hepatitis A and 8,230 people received immune globulin shots.
People concerned about having been exposed to hepatitis A are asked to call the Health Department at 1-877-724-3258. If risk factors warrant it, people can get immune globulin treatments at a state Health Department office in Beaver.
No cause has been determined in the outbreak, but investigators believe it was more likely a problem with food-worker hygiene than a food item that arrived at the restaurant already contaminated. The restaurant has apologized to patrons and said company policy prohibits sick employees from coming to work.
"However, given my understanding of the incubation period, several employees may have worked, not knowing that they had been infected or could pass on that infection to others," Bill Zavertnik, the chief operating officer of Chi-Chi's Inc., said in a statement.
Hepatitis A virus is contained in feces and an infected person can shed the virus for up to two weeks before symptoms appear.
Transmission of the virus from person to person requires more than just casual contact. Typically, a person is exposed to the virus by eating contaminated food or placing a contaminated utensil or other object in his mouth.
The virus incubates in an infected person for an average of 28 days. Many of those sick thus far were exposed during the first week of October. State officials are working to prevent the newly sick from passing on the virus to a new set of patients.
On Saturday, the state asked workers at another Beaver Valley Mall restaurant and two others in adjoining counties to receive shots of immune globulin, said John Stella, the state Department of Agriculture's regional supervisor for food safety. The antibody treatment lessens the chance of acquiring the disease if given within 14 days of exposure.
A worker at each of the restaurants has come down with hepatitis A, but state officials stressed there is no public health risk to patrons of the eateries.
A vaccine is available for hepatitis A and some restaurants around the country ask their employees to take it. In Branson, Mo., more than 300 restaurants participate in a voluntary program with public health officials that has resulted in two-thirds of the food-service workers in the community being vaccinated, said Veronica Fisher, spokeswoman for the Taney County Health Department.
To become immunized, people must receive two shots of vaccine -- the second coming between six and twelve months after the first. Immunity is thought to last at least 20 years. In Branson, each shot costs $25.
But most places in the United States, including Pennsylvania, don't require shots for restaurant workers, said Dr. Andre Weltman, public health physician with the Pennsylvania Department of Health.
The Chi-Chi's restaurant remains closed and has scheduled a news conference for tomorrow.
Central Blood Bank reported today that it has set aside four units of blood donated by people who ate at the restaurant in October. Blood bank officials say there is a minimal risk that donors exposed to hepatitis A could transmit the virus through their donated blood. Donors who ate at the restaurant between Oct. 1 and Nov. 2 are asked to call 1-866-366-6771.