Health risks may reach far beyond reported victims

— -- Like any mother facing a long day in the car and then on a plane with two young kids, ages 4 and 5, Jennifer Krieger of Alexandria, Va., was prepared.

"I bought peanut butter crackers," she says, "thinking it would be a great healthy snack to take on the trip, easy to throw in my bag, and it won't go bad."

But things went bad, in ways that Krieger couldn't have imagined. A long-awaited Christmas vacation ski trip turned into a five-day vigil at a Colorado hospital after David Krieger, 4, got salmonellosis, a life-threatening infection caused by exposure to the salmonella bacteria.

"The hardest part was seeing him in such pain," Krieger says. "He would cry out, 'My tummy hurts! My tummy hurts!' and he'd be in a fetal position on the floor."

Federal officials say David, who has recovered, was one of more than 538 people across the nation who became sick after they ate contaminated peanut butter or foods containing tainted peanut paste made in a Peanut Corp. of America (PCA) manufacturing plant in Georgia. The infection also may have contributed to eight deaths, they say. Recalled products now number more than 1,700, including peanut butter crackers and many other snacks, although officials say major brands of peanut butter are not affected.

PCA is under a criminal investigation by the Food and Drug Administration and the Justice Department. A second congressional hearing on the recall is scheduled for Wednesday. The impact of the salmonella contamination could reach well beyond the 538 people who got sick.

On Tuesday, the company suspended operations at its Plainview, Texas plant, ahead of its announcement that salmonella may have been found at the site.

An Associated Press investigation last week revealed that the Plainview plant, which opened in March 2005, operated uninspected and unlicensed by state health officials until after the company came under investigation last month by the Food and Drug Administration. Once inspectors learned about the Texas plant, they found no sign of salmonella there.

PCA had already closed the Blakely, Ga. plant last month after it was identified as the source of a salmonella outbreak.

On Monday, the FBI raided the plant in Georgia, hauling off boxes and other material. Agents executed search warrants at both the plant and at Peanut Corp.'s Lynchburg headquarters, according to a senior congressional aide with knowledge of the raids. The official spoke only on condition of anonymity because he was not authorized to speak publicly on the matter.

The conventional wisdom among epidemiologists, first outlined in a 2004 paper by Centers for Disease Control and Prevention researcher Andrew Voetsch, is that for each case of salmonellosis that is reported, more than 38 other people get sick but don't go to their doctor or get tested. So this outbreak could be responsible for more than 20,000 illnesses.

In Belle Plaine, Minn., pre-Christmas snacking was the likely path to infection for Sarah Kirchner's son Michael, 3. "We ease up around Christmastime," Kirchner says, so Michael got to eat more peanut butter crackers and candy than he'd normally be allowed.

He was in the hospital for four days, three with a temperature of 104. "He couldn't even move because he was in so much pain. He would scream and cry every time the nurses touched him," Kirchner says.

Michael's baby sister Lily, who was 4 months old, got the bug from him. The bacteria can be passed along via contaminated hands and surfaces. And it was present and growing in Michael days before his parents knew he was sick.

Lily got to stay at home but had such intense diarrhea every five to 10 minutes that her skin was raw and she had to have a baking-soda bath after each bout to counteract the acid in her stool.

Kirchner and husband David — who had not eaten the crackers or candy — took turns at home and in the hospital so that neither child was ever alone.

"I kept wishing it was us," she says. "Why didn't we get it?"

Most fight off infection

Once ingested, the salmonella bacteria start growing in the intestines. For the vast majority of people exposed, their bodies fight it off, and they never know they had it.

But depending on how many bacteria you have, or how old or sick you are, salmonella can overwhelm the body's defenses and infect the colon, says Tim Dellit, an infectious-disease specialist at Harborview hospital in Seattle.

"Normally you've got this nice, smooth intestine and colon, and then you get inflammation, and it's like eczema on your skin," Dellit says.

In some cases, blood vessels leak into the colon, he says.

"It can actually be bright red blood that comes out in the watery diarrhea. That's typically what people will notice, that there will be blood in the toilet bowl."

In most cases, salmonella infection lasts four to seven days. The body eventually fights it off. In fact, treating it with antibiotics often can make it worse. "In some situations, the antibiotics can prolong the carrier state, the time that the body takes to clear the bacteria," Dellit says.

How hard salmonella hits a given person depends on several factors: how much bacteria they consumed, how good their immune system is at fighting it off and how old or young they are.

But there's another interesting thing about salmonella: There are thousands of different strains of the bacteria, and each seems to attack the body in a slightly different way, says Robert Tauxe of the CDC's division of foodborne, bacterial and mycotic diseases.

There are salmonella strains that hit younger people harder, and there are salmonellas that hit older people harder. Some make boys sick more than girls; some, women more than men. In the ConAgra salmonella outbreak associated with peanut butter in 2007, more than 25% of the cases showed up as a urinary tract infection in older women, researchers at the CDC found.

Why the same basic bacteria cause such different illnesses is a mystery. "It's a real head-scratcher," Tauxe says. "I can't pretend we understand why."

The current outbreak's potential impact on children likely has been reduced by the rise in peanut allergies in the USA. Salmonella is most dangerous for very young children.

"Pediatricians have told everybody under 2 to stay away from peanut butter" for the past few years, Tauxe says.

"So we see very few kids under the age of 2 in this outbreak," he says. "And those are likely to be the kids who get into trouble."

What are the chances?

Leslie Kurland of Hoosick, N.Y., went to culinary school, so she knows all about food safety and sanitation.

But it never occurred to her that peanut butter crackers could be the cause of the horrific bout of salmonella that has son Gabriel, who is about to turn 2, on his second round of antibiotics.

In his case, doctors prescribed antibiotics because very young children are at the highest risk for developing a blood infection from salmonella.

Overall, however, salmonella has a very low attack rate, says Bill Keene of Oregon's acute and communicable disease program.

"Look at the total number of people ill, we're talking 500 reported cases," says Donald Schaffner, a food microbiologist speaking for the Institute of Food Technologists.

"But the amount of product that came out of that (PCA) plant fed more than 20,000 people. So we're looking at a level of contamination that's low and sporadic."

Peanut butter and peanut paste, which are low in water and high in fat, are an almost perfect medium to preserve salmonella bacteria even when they are exposed to heat.

That's a problem, because the "kill step" for peanut butter — the action that's supposed to ensure that it's free of harmful bacteria — is roasting, Schaffner says.

That means that either the roasting of the contaminated products wasn't done at a high enough temperature or the peanut products were infected later in the process.

A recent FDA inspection found unsanitary conditions at the PCA plant. An FDA inspection report says PCA shipped products in 2007 and 2008 that tested positive for salmonella.

In some situations, the products first tested positive and then negative — and then were shipped anyway. In others, the company shipped products before receiving positive test results, the FDA report says.

A wake-up call

Peanut paste goes through more heat exposure when it's baked in a cracker or some other kind of snack.

However, "Salmonella is a million times more heat-resistant when it's in peanut butter than when it's in chicken (a common carrier) or another high-moisture environment," Schaffner says.

This outbreak is a wake-up call to the nut industry and the food industry in general, Schaffner says.

"People (in the industry) ought to be asking themselves, 'What is my kill step? Am I really sure that my kill step is as effective as I think it is?'

"If there's anybody out there in the industry who's manufacturing nuts or nut butter of any kind, they really need to get on the stick and study the thermal processes they're using and document that it's effective against salmonella."

For now, the only thing that's going to end this outbreak is for people to go through their cupboards and toss out potentially infected food.

"The shelf life of these products is months, if not years, in somebody's cupboard," says the CDC's Tauxe.

"They're going to be little time bombs going off for months unless people get rid of them."

Contributors: Associated Press