The Centers for Disease Control and Prevention (CDC) has joined the Michigan Department of Health in  investigating an unusually large outbreak of shigellosis in Saginaw and Genessee counties, where the city of Flint is located. The outbreak, caused by the Shigella bacterium, has sickened 177 people since March, with at least 27 people hospitalized because of the severity of their illness. The main symptom is watery diarrhea, but abdominal cramping, nausea and vomiting may also occur. Hospitalization from shigellosis is rare but can be necessary because of dehydration.

The illnesses in this outbreak were reported to public health officials between March 1 and Oct. 26, 2016. There are typically some 300 to 400 cases of shigellosis in Michigan every year, so authorities consider 177 in just two counties a disproportionately high number. The bacteria is usually introduced via the fecal-oral route but then spreads quickly from person to person when hands aren’t washed. For example, a foodservice worker might change a baby’s diaper, fail to wash her hands, go to work and spread the Shigella bacteria

Some think that the water crisis in Flint, which was created when an administrator switched the city’s water supply to the Flint River, may have contributed to this outbreak since residents are now fearful of using the water to bathe. The best way to prevent the spread of this illness is proper handwashing. Washing your hands with soap and water for at least 20 seconds is the best way to remove any bacteria from your hands. Hand sanitizers that contain at least 60 percent alcohol will kill Shigella bacteria, but don’t work well if  hands are greasy or very dirty. Baby wipes do not kill Shigella.