Foodborne illness outbreak investigation summary
Update posted September 12, 2016
The investigation is continuing to evolve, and information may change.
In addition to the 5 known ill people described in our original update on Friday 9/9 who ate at Matador, we are aware of 5 other people who became ill with the same strain of E. coli as the people who ate at Matador.
We are aware of 2 other Washington state residents (who are not King County residents) and 3 out-of-state residents who are positive for E. coli with the same strain of E. coli as the King County cases we previously reported on. Investigation of those cases is ongoing by their respective health departments. We just became aware that one of the out-of-state cases had a meal at the Matador restaurant in Ballard during the exposure period. Links to Matador have not been identified among the other out-of-county cases. We are not aware of links to restaurants other than Matador at this time.
The genetic fingerprint or "PFGE" is similar across all these cases. This particular E. coli strain has not been seen before in Washington state. August 22nd is the last known meal date for people who we know got sick after eating at Matador. Therefore, it is unlikely that the outbreak is continuing, though it is possible that public health authorities will continue to find people who became sick later in August or early September.
A little bit about the timing in food borne illness investigations: A person with an E. coli infection can take a week or more to develop symptoms. Then the ill person needs to go to his/her doctor. A stool sample is taken, which is sent to the lab, and it can take several days for the results to become available. The lab or the physician then reports positive results to Public Health, who attempts to contact the patient and conduct one or more interviews. Frequently, we don't reach the person on the first attempt and we need to interview cases more than one time to identify commonalities. Four of the five cases in King County did not report eating at the Matador when they were initially interviewed by Public Health staff.
Restaurant inspection findings: As soon as we were able to determine that there was a link to Matador restaurant, we inspected and suspended the permit to operate. We found that there was the potential for cross contamination based on inadequate cleaning of the food processing machines (e.g. food processor) and there was inadequate cleaning of some produce. We do not know if either of these contributed to the outbreak.
What's next in the investigation? We will continue to collect information from the people who have gotten sick. We are working with the Washington State Department of Health to gather information on out-of-county cases and have reported our preliminary findings to the CDC.
We will be taking environmental samples at the restaurant to see if it's possible to identify a source product, but at this time, we do not have a suspect ingredient. Items on the menu share many ingredients in common, so it's possible we may not be able to positively identify the source of the E. coli. We are also collecting information to ensure that no employees are working with possible E. coli infections; preliminary reports are that no workers have been ill.
At this time, there is no action members of the general public need to take in relation to this outbreak. However, any one who gets bloody diarrhea, even if they didn't eat at Matador, should consult a health care provider.
Posted September 9, 2016
Public Health is investigating a cluster of five E. coli infections caused by Shiga-toxin producing E. coli (also called STEC) associated with Matador restaurant in Ballard. Four people ate on 8/14 and one person ate on 8/22. Public Health received the first report of illness on 8/22/16 and the most recent case was reported on 9/6/16. All the people developed symptoms including diarrhea and abdominal cramps. Four people developed bloody diarrhea. Three people had been hospitalized with one person developing a type of kidney injury called hemolytic uremic syndrome (HUS). All five people have recovered.
Laboratory testing (molecular fingerprinting) has determined that all five people have the same strain of STEC bacteria. Our investigation is in progress but due to food processing equipment cleaning and the possibility of cross contamination that were observed during an inspection by our Environmental Health team, Public Health has temporarily suspended Matador's food business permit to allow time for thorough cleaning and sanitizing. The restaurant is working cooperatively with Public Health.
Persons who have eaten at Matador and developed diarrhea within 10 days and anyone who develops bloody diarrhea should consult with their healthcare provider to determine if testing is necessary.
STEC and other foodborne infections occur year round but may increase during the summer months. If you or your child develop new painful or bloody diarrhea, contact your healthcare provider to see if testing for STEC is needed.
E. coli bacteria normally live in the intestines of humans and animals. Many strains of E. coli bacteria exist, and most of them are harmless or beneficial to human health. STEC are strains of E. coli that produce Shiga toxin (such as E. coli O157:H7) and can cause serious illness in people.
Infection with STEC can occur through consumption of undercooked ground beef and other beef products; unpasteurized (raw) milk, cheese, and juice; contaminated raw fruits, vegetables, sprouts and herbs; water contaminated with animal feces, or by direct contact with farm animals or their environment. Ready-to-eat foods can also be contaminated with STEC through contact with raw beef or raw beef juices in the kitchen.
Symptoms of STEC include diarrhea (which often becomes bloody) and stomach cramps, with mild or no fever. Illness typically lasts several days and people can spread infection to others even after symptoms resolve.
To prevent STEC infection:
- Avoid eating high-risk foods, especially undercooked ground beef and other beef products, unpasteurized (raw) milk or juice or cheese, and raw sprouts.
- Use a food thermometer to make sure that ground beef has reached a safe internal temperature of 160° F.
- Wash hands before preparing food, after diapering infants, and after contact with cows, sheep, or goats, their food or treats, or their living environment.
- Thoroughly wash fresh produce before eating.
For more information about STEC, see: