The U.S. Centers for Disease Control and Prevention warned consumers on Tuesday to not eat romaine lettuce as it may be contaminated with E. coli.

A total of 32 people, including 13 who have been hospitalized, have been infected with the outbreak strain in 11 states, according to the CDC. One of the hospitalized developed hemolytic uremic syndrome, a type of kidney failure. No deaths have been reported.

The Public Health Agency of Canada has identified an additional 18 people who have become sick with the same strain of of E. coli in Ontario and Quebec.

If you have any brand or type of romaine lettuce at home, you should throw it away, even if you ate some and did not get sick, the CDC cautioned. Retailers and restaurants also should not serve or sell any until more is learned about the outbreak. All brands of romaine lettuce are suspect because no common grower, supplier, distributor or brand has been identified by the CDC.

Symptoms, which usually begin about three to four days after consuming the bacteria, can include watery or bloody diarrhea, fever, abdominal cramps, nausea and vomiting, according to the CDC. Most people infected by the bacteria get better within five to seven days, though this particular strain of E. coli tends to cause more severe illness.

Illnesses started in October. The current outbreak is not related to a multistate outbreak linked to romaine lettuce this summer.