The CDC’s Patricia Griffin recently commented on antibiotic treatment of E. coli infection in a September, 2006 Clinician Outbreach and Communication Activity conference call, during the E. coli O157:H7 outbreak traced to spinach grown in California’s Salinas Valley:

If you strongly suspect E. coli O157, there are some concerns about antibiotic treatment. Whenever a person has diarrhea, it’s important to hydrate them.

We know that there are fluid losses in diarrhea, and hydration is very important. And Dr. Tarr is going to talk more about the particular importance of hydration in E. coli O157 infections. Also in colitis, there are data indicating that giving Imodium or loperamide can increase the risk of complications, and we do not recommend that for E .coli O157.

In particular, there’s some retrospective data suggesting that the use of antidiarrheals could actually increase the risk of complications. With E. coli O157, there are some particular concerns about antibiotics, and those concerns come from looking back at people who have been treated with antibiotics. And some of these people have been more likely to develop hemolytic uremic syndrome.

There are many reasons why looking back at treatment can be a biased way of making decisions, but we’ve also looked at whether antibiotics have helped in the treatment of E. coli O157, and we haven’t found any good data that patients who were treated with antibiotics actually did better.