Missouri health officials have tied the strain of E. coli that sickened 115 people in the region to other outbreaks in Illinois, North Dakota, South Dakota, Ohio, Kansas and Indiana.
Workers at the Missouri State Health Laboratory in Jefferson City sequenced the genome of dozens of samples taken from those infected in the outbreak, St. Louis County officials announced Tuesday. Lab workers linked 25 cases to St. Louis County-based Andre鈥檚 Banquets and Catering.
Entering that so-called 鈥済enetic fingerprint鈥� into a national database showed it matched outbreaks in the West and Midwest, St. Louis County Department of Public Health Senior Epidemiologist Amanda Brzozowski said.
鈥淲e found that the same genetic fingerprint popped up on a number of other cases in several other states,鈥� she said, 鈥淎 couple of those states have what they call subclusters, where they have more than one case that would have been exposed at the same place or at the same time.鈥�
County health experts say that could indicate contamination from a food source or a distributor.
In a statement, a spokesman for Andre鈥檚 said those at the business looked forward to more information coming to light.
鈥淭oday, they confirmed genetic sequencing of local cases has now connected the outbreak with cases in at least six other states,鈥� he said. 鈥淲e have said all along that it was unfair to name Andre's before the lettuce was tested and before the investigation was complete.鈥�
County health officials began investigating the outbreak in mid-November when several people got sick after eating at events sponsored by Rockwood Summit High School. The health department eventually linked cases to at least four events catered by or held at Andre鈥檚.
More than a dozen people were hospitalized, and three were diagnosed with a potentially fatal kidney disease associated with E. coli.
Brzozowski said that the strain involved in the outbreak, HO157, can cause particularly serious complications and is usually associated with painful cramping and diarrhea.
The outbreak has spawned an 鈥渋ncredible amount of cases,鈥� said Sami Friederich, a disease investigator with the county health department.
鈥淚 think last year we had a handful of E. coli 0157 cases,鈥� she said. 鈥淎nd then suddenly, at the beginning, we get three in one day. And then it has just grown from there to over 100.鈥�
She said now that not as many cases are being reported, it鈥檚 largely up to federal agencies to find links with other national outbreaks, including the Centers for Disease Control and Prevention, the Department of Agriculture and the Food and Drug Administration.
鈥淪o all of the national federal partners are involved,鈥� Freichrich said.
That could mean tracing the outbreak to a supplier or distributor.
That鈥檚 what happened earlier this year, when officials eventually tracked another national outbreak of the same E. coli strain to McDonald's Quarter Pounder hamburgers that contained contaminated onions associated with a California food company.
Although the recently completed genetic tests cannot definitely link the local cases to any specific food product, county health officials suspect salad is the culprit for the local infections.
The vast majority of the affected people reported eating salad, Brzozowski said.
鈥淟eafy greens are uncooked,鈥� she said. 鈥淪o anytime you're eating something raw where there's no kill step, you're a lot more likely to get sick. 鈥� There's lots of places for the bacteria to hide.鈥�
