Fast food chain Chipotle has closed 43 restaurants after an E. coli outbreak in Washington state and Oregon.
As of Friday, three people in the Portland area and 19 people in western Washington have fallen ill. Eight people have been hospitalized, but no deaths have been reported. Doctors expect the number of cases to rise.
There are hundreds of E. coli and similar bacteria strains in the intestines of humans. Most are harmless, but a few can cause serious problems.
Symptoms of E. coli infection include diarrhea, abdominal cramps, nausea and vomiting. Health officials say the best defense against the bacterial illness is to thoroughly wash hands with soap and water.