Escherichia coli is a strain of bacteria present in the intestinal tracts of humans and some animals. When ingested, it can be pathogenic and, hence, is a threat to food safety. In 1982, E. coli 0157:H7 was first isolated in cattle. It is a virulent and potentially lethal foodborne pathogen that may have been in the food system for decades before it was discovered. In an estimated 4 percent of cases, E. coli 0157:H7 produces shiga toxin that attacks the lining of the intestine and enters the bloodstream, causing hemolytic uremic syndrome (HUS), which can lead to kidney failure, anemia, internal bleeding, and other complications, including death. To be infected, one only need ingest as few as five organisms, which could be in a microscopically small piece of uncooked hamburger. People remain contagious for about two weeks.

From infected persons, E. coli is shed in stool; it can be spread from person to person through poor hygiene. Cattle infected with E. coli 0157:H7 can appear healthy for years and show few signs of illness. Foods tainted by this pathogen have most likely come in contact with an infected animal’s stomach contents or its manure. Huge feedlots, slaughterhouses, and hamburger grinders have dispersed this pathogen into the nation’s food supply.

In 1993, Jack in the Box suffered an outbreak of E. coli 0157:H7. About 10 percent of those afflicted did not eat a contaminated hamburger but were infected by someone who did. Since then, it is estimated that approximately 500,000 Americans have been made ill by E. coli 0157:H7. Of these, thousands have been hospitalized and hundreds have died. To date, antibiotics have proven ineffective in treating E. coli -related illnesses. It is resistant to salt, acid, and chlorine; it can live in fresh or seawater; it can withstand freezing and high temperatures (up to 160 degrees F). The only known methods to prevent it from entering into the food supply chain are improved testing and cooking beef (hamburger) and chicken to temperatures higher than 160 degrees F.