The hospitalization rate and hemolytic uremic syndrome case count in the deadly E. coli O157:H7 HUS outbreak that is linked to romaine lettuce has been very high. Typically, in an E. coli outbreak, about 30% of patients are hospitalized, and about 5 to 10% develop hemolytic uremic syndrome (HUS).
But in this outbreak, the hospitalization rate is almost 50%, and 13% of those patients have developed HUS. Why is the hospitalization rate and the HUS rate so high in this particular outbreak?
Typically, the group most susceptible to developing HUS is children under the age of 5. The patient age range in this outbreak is from 1 to 88. There could be quite a few children sick, which may explain the high HUS rate.
Another explanation for the high HUS rate and the high hospitalization rate is the type of toxins the E. coli bacteria are producing. Shiga toxin-producing E. coli bacteria make two types of those toxins: Stx1 and Stx2. Unfortunately, the bacteria in this outbreak are making Stx2, which causes more damage to the body.
Another factor could be that the lettuce was contaminated with an unusually high number of bacteria. It takes just 10 E. coli bacteria to make someone sick. More bacteria can release more toxins and cause more damage.”