CDC Provides Update on Multistate Outbreak of E. coli O157:H7 Infections

On Jan. 10, 2018, the Public Health Agency of Canada reported that an outbreak of Shiga toxin-producing E. coli O157:H7 infections (STEC O157:H7) they had identified linked to romaine lettuce appears to be over. In the United States, the Centers for Disease Control and Prevention (CDC), several states, and the Food and Drug Administration (FDA) continue to investigate a multistate outbreak of 24 STEC O157:H7 infections in 15 states. Since CDC’s initial statement on Dec. 28, seven more illnesses have been added to this investigation. The last reported illness started on Dec. 12, 2017.

The likely source of the outbreak in the United States appears to be leafy greens, but officials have not identified a specific type of leafy greens eaten by people who became ill.  Leafy greens typically have a short shelf life, and since the last illness started a month ago, it is likely that contaminated leafy greens linked to this outbreak are no longer available for sale. Canada identified romaine lettuce as the source of illnesses there, but the source of the romaine lettuce or where it became contaminated is unknown.

Whole genome sequencing (WGS) showed that the STEC O157:H7 strain from ill people in the United States is closely related genetically to the STEC O157:H7 strain from ill people in Canada. WGS data alone are not sufficient to prove a link; health officials rely on other sources of data, such as interviews from ill people, to support the WGS link. This investigation is ongoing. Because CDC has not identified a specific type of leafy greens linked to the U.S. infections, and because of the short shelf life of leafy greens, CDC is not recommending that U.S. residents avoid any particular food at this time.

Symptoms of E. coli Infections
Most people develop diarrhea (often bloody) and stomach cramps. People usually get sick from E. coli O157:H7 three to four days after eating food contaminated with the germ. If you are concerned that you have an E. coli infection, talk to your healthcare provider.

General Recommendations for Preventing E. coli Infections
You can protect yourself by washing your hands thoroughly before and after preparing or eating food. You can also wash counters, cutting boards, and utensils after they touch raw meat to avoid contaminating other foods. It’s also important to avoid preparing food when you are sick, particularly if you are sick with diarrhea.

For more information about this outbreak, visit https://www.cdc.gov/media/releases/2018/s0110-update-ecoli.html