E. coli bacteria live in the large intestine of all healthy people and most mammals. There are more than 150 different types.
Most cases of E. Coli meningitis occur in newborn babies and the elderly. Less often it occurs in those with suppressed immune systems weakened by AIDS, cancer, diabetes, immune suppressing drugs following organ or bone marrow transplant, and other disorders.
Infection in newborns occurs during delivery, from bacteria normally present in the birth canal. Premature and low birth-weight babies are at much higher risk. It is a very serious disease. Approximately 20% of newborns die in spite of treatment and many survivors sustain permanent brain damage. Because most cases occur in premature infants it is difficult to determine how much of the damage is due to meningitis and how much is the result of premature birth.
E. coli meningitis is treated with antibiotics and in spite of much research no vaccine has yet been developed.