Outbreak of E coli Infections Linked to Ground Bison

The US Centers for Disease Control and Prevention (CDC) and US Food and Drug Administration (FDA) have announced that they are collaborating with the Canadian Food Inspection Agency to investigate a multistate outbreak of E coli O103 and E coli O121 infections.

Early epidemiologic and traceback information point to ground bison products as the likely source of the outbreak.

As of July 12, 2019, there have been 21 individuals infected with E coli in this outbreak. In total, 6 individuals have been infected with the O103 strain, 13 cases of the O121 strain have been confirmed, and 2 individuals have been found to be infected with both strains.

Cases related to this outbreak have been documented in US 7 states, with onset of illness dates ranging from March 18 to June 18, 2019. The ill range in age from 6 to 79 years, with a median age of 25 years. Information is available for 17 of the ill individuals, of which 8 (47%) have been hospitalized. Fifty-two percent of the ill are female. Illnesses that began after June 22, 2019, may not be reported yet due to the length of the E coli reporting timeline.

As part of the outbreak investigation, ill individuals answered questions about consumptions and exposures in the week prior to falling ill. According to the CDC, of the 9 individuals for whom information is available, 6 (67%) reported that they ate or possibly ate ground bison.

Health officials pinpointed restaurants where patients reported eating ground bison burgers and collected records regarding suppliers of the meat. The records indicate that ground bison produced by Northfolk Bison Distributions, Inc., was served in multiple restaurants where the ill ate ground bison prior to falling ill.

As a result, Northfolk Bison Distributions, Inc., a Saint-Leonard, Quebec, Canada-based company, issued a recall for ground bison and bison patties produced between February 22, 2019, and April 30, 2019. Federal health officials remind consumers and retailers that recalled products should not be served or sold.

Individuals typically fall ill from Shiga toxin-producing E coli 3 to 4 days following contact with the germ. Symptoms can include severe cramps, bloody diarrhea, and vomiting, which may persist for 5 to 7 days. Clinicians should be cognizant that patients presenting with these symptoms may be infected with E coli.

Antibiotics are not recommended for patients with suspected E coli infections until testing can rule out the food-borne infection. The CDC notes that studies have shown that antibiotic use in the presence of E coli could lead to increased risk for hemolytic uremic syndrome. No deaths and no cases of the syndrome, which is a type of kidney failure, have been reported in this outbreak at this time.

This is an ongoing investigation and the CDC will provide updates as they become available.

For a list of states and cases counts in the E coli outbreak linked to ground bison, visit the Contagion® Outbreak Monitor.