021041 Group Finds New Food Poisoning Items

Chicago - Bad tomatoes? Nasty butter? Disgusting chili? Experts gathered this weekend for an infectious disease conference added some unusual suspects to the long list of foods that can make people sick.

Nationwide, the food supply is getting safer. Outbreaks of food poisoning have been declining since the mid-1990s, and often those that do occur are traced to such predictable sources as undercooked meat or raw chicken.

But presentations at this year's meeting in Chicago of the Infectious Diseases Society of America are a reminder that even the most innocuous sounding grocery items can be dangerous when something goes wrong, usually in the way they are processed or handled.

"It's ever changing," said Dr. Jenny Lay of the Centers for Disease Control and Prevention. "The outbreaks today are very different from the ones 10 or 20 years ago."

The CDC and other agencies still investigate outbreaks involving a few dozen people in a single small town — the classic church supper incidents. But often outbreaks these days are harder to recognize. They involve small numbers of people spread over the entire country, all victims of broadly distributed foods contaminated at some point in production.

Bean sprouts, mangoes, almost anything people eat can do the job if they somehow become tainted with a variety of toxic organisms, such as salmonella or E. coli. At conferences such as this one, investigators often concentrate on cases in which the bug, the food or both are out of the ordinary.

That turned out to be the case last year in Nassau County, N.Y., when nearly 900 people got sick after eating at five restaurants with the same proprietor. The germ was an unusual one, Shigella flexneri. And the food? Bruised tomatoes.

The restaurants had acquired the "special grade" tomatoes from one source. They were shipped unrefrigerated and never washed. Investigators suspect they somehow get contaminated at the distributor.

Knowing the intimate details of such chains of events can definitely affect disease investigators' views about eating out, or even in.

"After a while, you start thinking about all the things that happen to food before it goes into your mouth," said the CDC's Dr. Pavari Kalluri. "It can deter your enjoyment."

Kalluri investigated an outbreak of botulism in Sanger, Texas, last year that was the country's largest in seven years.

Fifteen of the 16 victims had attended a church supper, and three became so sick they had to be put on breathing machines. It turned out they had eaten a dish made from frozen chili that was bought at a food salvage store. The investigators believe that somewhere along the line, the chili had been allowed to thaw.

In a Robeson County, N.C., school last November, 186 students came down with diarrhea after a homemade butter demonstration. The germ turned out to be E. coli 0157:H7. This is an especially nasty bug that causes an estimated 73,000 cases of diarrhea annually and more often spreads in undercooked hamburger. The investigators said the butter, which the students sampled, was made from unpasteurized milk.

Perhaps the oddest outbreak of the 0157 bug occurred last year at the Lorain County Fair in Ohio. Many of the victims had gone to a barn dance in a building used earlier to show animals. Apparently their stomping stirred up bacteria in leftover manure.

"You'll find a lot of things here that will kill you," said Dr. Peter Daley of the University of Calgary in Alberta, Canada.

His example was ciguatera, poisoning caused by eating warm-water reef fish that have accumulated naturally occurring toxins through their diet. About 20 members of a family got sick after eating grouper, surgeon and snapper brought home frozen from Fiji.

Daley said doctors need to keep this disease in mind, especially if patients complain of intestinal upsets and unusual numbness and tingling, although he conceded, "It's very rare. I don't expect to see another case in my career."

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