Jack In The Box Poisonings -- Food Safety Standards Higher Here -- Cooking Temperature For Hamburgers Increased To 155 Degrees

Some fast-food customers are still asking for rare hamburgers - despite massive publicity surrounding the outbreak of deadly E. coli illness in Washington.

Paul Thicich, manager of a Kirkland Burgermaster said a customer requested a rare burger yesterday, but he said, "No way. We're not going to open ourselves to that."

Health officials say a combination of contaminated meat and undercooking by some Jack in the Box restaurants probably caused the E. coli outbreak that has killed one child and made about 160 people sick.

Since May 1, Washington state has required restaurants to cook hamburger to an internal temperature of 155 degrees, replacing the old 140-degree rule. It's the highest temperature requirement for hamburger in the country. Most states remain at 140 degrees.

The dangers of E. coli 0157:H7 prompted the change in Washington. Two elderly Walla Walla women died in a 1986 E. coli outbreak, and several children became sick in a 1984 outbreak in Spokane.

Less publicized are the cases that occur every year in smaller clumps - 150 to 200 of them, with about one death every one or two years. Most are linked to summertime home barbecues and picnics.

Here's how food-safety experts arrived at the 155-degree cooking temperature:

Their goal was something they call thermal death time - the cooking time and temperature required to kill dangerous bacteria.

At first, it looked like a 165-degree meat temperature was

needed to do the job on E. coli, says Bert Bartleson, technical expert for the state Health Department.

But the fast-food industry objected to 165 degrees. They didn't want their burgers "tasting like hockey pucks," says Bartleson.

The state then consulted with Michael Doyle, now at the University of Georgia and considered the country's leading expert on E. coli. Doyle's research indicated that cooking hamburger to the old temperature of 140 degrees for 45 seconds kills 90 percent of the organisms - not good enough.

Bartleson says Doyle - who had been hired by burger giant McDonald's to do some of the cooking studies - found that cooking hamburger to 150 degrees would destroy 99.999 percent of the bacteria. The state considered that acceptable, but tacked on five more degrees to be extra safe, says Bartleson.

Using an electronic temperature-reading device, Bartleson this week tested meat cooked at Jack in the Box under its old system and said it registered only 143 degrees - far below the new state standard. The chain says it has since increased its cooking time to reach the required 155 degrees.

But a new question has arisen: If the contamination level in meat is extremely high, could a tiny amount of E. coli 0157:H7 remain even after proper cooking - enough to make a person sick?

Laboratory tests this week revealed a very high level of coliform in the implicated Jack in the Box meat. E. coli is part of the coliform family of bacteria.

Only a minute amount of E. coli 0157:H7 - perhaps just two or three bacteria in a gram of meat - are enough to make a person sick, Bartleson said. The high coliform contamination would make it harder to kill all the bacteria through normal cooking procedures, he said. But he added that even when overall coliform levels are high, E. coli 0157:H7 levels are usually extremely tiny.

"I would never say never," Bartleson said, "but I would say the odds are infinitesimally small" that these bacteria would remain after cooking to 155 degrees.

He said county health officials around the state spot-checked fast-food restaurants this week and found widespread compliance with the 155-degree rule - no surprise, given the flood of E. coli publicity. He said there were "a few isolated incidences" of noncompliance.