In 1982, after a puzzling series of apparent and sometimes lethal sort of food poisoning, a strain of bacteria was discovered. This was the E. coli O57:H7. Our bodies and those of animals are loaded with E. coli bacteria and most are useful. Some, for example, help us to utilize vitamins. E. Coli O157:H7, however, was bad news.

What is E. coli O157:H7?

It is one of hundreds of strains of Escherichia coli, most of which are harmless. They live in the intestines where many of them do good work. Probably the result of a mutation, the E. coli O157:H7 is found in the intestines of cattle where it does no harm but it is transferred to humans to whom it makes sick. It has also been found in sprouts, lettuce, salami, raw milk, un-pasteurized milk, and untreated water. The e coli on the vegetables got there by coming into contact with raw meat or with the hands of an infected person.

What does E. coli O157:H7 do to humans?

Each year about 73,000 cases of food poisoning and 63 deaths are due to E. coli O157:H7 according to the CDC. Recently there has been a 35% decline.

In most cases it causes cramping and bloody diarrhea. Anyone with blood in their stool should be tested for e coli. It runs its course in 5-7 days. Anti-biotics are ineffective and anti-diarrheal medications should not be used. Children under the age of five, the elderly, and people with compromised immune systems are at risk for developing a condition called hemolytic urenic syndrome in which the red blood cells are destroyed and the kidneys fail. These cases are usually treated in intensive care units where patients receive blood transfusions and kidney dialysis. With intensive care, the death rate is about 3% to 5%.

Usually there is complete recovery from a simple case of poisoning by e coli but those who have had hemolytic uremic syndrome often have life long complications. About one third have abnormal kidney function many years later, and a few of these require transplant or dialysis. Another 8% have high blood pressure, seizures, blindness, and paralysis.