"Sheetz kept coming up, and not just one Sheetz, but Sheetz that were spread around the state," health department spokesman Richard McGarvey said Wednesday. The number of cases is likely to continue to climb, although health officials aren't willing to speculate how high.
Sheetz customers who ate store-prepared deli sandwiches or salads between July 2 and 8 became sick. Symptoms of diarrhea, fever and abdominal cramps hit 12 to 72 hours after they were infected.
The tainted produce, possibly plum tomatoes, was packaged in individual servings by a food distributor.
"All 34 cases are the same type, which is surprising. ... That says to us it is a single-source outbreak," McGarvey said. He said the produce was not contaminated at Sheetz.
"We didn't find any problems with cooking or hygiene in the stores," McGarvey said.
In addition to Allegheny, Beaver, Butler and Westmoreland counties, salmonellosis has been confirmed in Washington, Indiana, Franklin, Bedford, Fulton, Clearfield and Dauphin counties, McGarvey said.
Salmonellosis also has been reported in Maryland and West Virginia, he said.
The type of salmonella identified in those who became ill is javiana, which most often is found in fresh produce. Javiana illnesses have been associated with produce and other foods, such as chicken, and with contact with reptiles, McGarvey said.
"While we do not have final confirmation on the source at this time, we continue to take steps to ensure the safety of all products sold in our stores," company Chairman Steve Sheetz said last night at a news conference at the organization's headquarters in Altoona.
"The well-being and safety of our customers and employees is our absolute priority."
Sheetz said the company became aware of the problem Friday when state Department of Agriculture investigators went to a store in Westmoreland County.
Two or three customers who ate at the store over the Fourth of July weekend had gotten ill, investigators told the company. The investigators went to a nearby store where another person who had gotten ill had eaten over the holiday.
Sheetz will not identify those stores. The health department was unable to supply a
county-by-county breakdown of cases.
Health officials have differing opinions on when public disclosure of the onset of the illness should be made.
Dr. Erick Berquist, an infectious disease specialist at Latrobe Area Hospital, said that "in general, it would be inappropriate to get people excited without knowing the cause" of the illness.
But McGarvey said health department officials would not wait until they are 100 percent sure of the source before announcing it.
"When everything starts to point somewhere then we say, 'That might be it,'" he said.
Then the department will step in to eliminate the source. He said, for the most part, the sources of such outbreaks voluntarily do what is necessary to eliminate the infection.
"It's not that you have to force people to do that," he said. "That's usually a fairly easy process."
The Department of Health began looking for the source and initially narrowed it down to what they felt might be lettuce or plum tomatoes, Sheetz said.
All those who became ill reported eating at Sheetz stores and having lettuce or tomatoes on their sandwiches or salads.
Sheetz stores sell lettuce and tomatoes only on items prepared by food handlers at the store. The stores do not sell produce.
Sheetz Inc. immediately replaced all lettuce and tomatoes from its approximately 300 locations in Pennsylvania, Ohio, West Virginia, Maryland, Virginia and North Carolina.
"We removed the lettuce and tomatoes, sanitized (the food preparation areas) and started all over," Sheetz said.
Although the health department is still conducting tests, the company learned yesterday that the tomatoes may be the culprit.
The Centers for Disease Control and Prevention in Atlanta has linked javiana to plum tomatoes in the past.
Mike Magner, director of safety and risk for Sheetz Inc., said the company is no longer using plum tomatoes. Instead, it is using hothouse tomatoes.
Magner also said the company has found a new tomato supplier. Neither Magner nor Sheetz would identify the previous supplier, which is still providing the company with lettuce.
However, a federal official familiar with the investigation said Coronet Foods in Wheeling, W.Va., is a produce distributor to Sheetz and is being investigated by state health officials. Coronet officials did not return phone calls.
McGarvey and officials with the Allegheny County Health Department are not sure that the area's seven cases of salmonellosis diagnosed this month are connected to the outbreak. Allegheny County may be taken off the list, McGarvey said.
Javiana was the fifth most common type of salmonella to infect humans in 2002, accounting for 3.7 percent -- or 1,188 -- of the nation's 32,308 cases of salmonella that year, according to the CDC.
Staff writers Cara Hayden, Richard Gazarik and Craig Smith and The Associated Press contributed to this report.