On September 14, 2005 the Concord Hospital laboratory submitted an E. coli O157:H7 isolate to the New Hampshire Department of Health and Human Services (NHDHHS) Public Health Laboratory (PHL) for confirmatory testing. The isolate had been cultured from a stool sample obtained from Hercules Tsirovakas. The next day the Communicable Disease Control and Surveillance section at NHDHHS received a facsimile from the Dartmouth Hitchcock Medical Center notifying them that transfer patient, Hercules Tsirovakas, was infected with E. coli O157:H7. The NHDHHS PHL issued a laboratory report confirming the diagnosis on September 16.
Health department investigators were unable to reach Christine Tsirovakas who was by her son’s side at the hospital. On September 20 investigators spoke with Donald Langlois, Hercules’ uncle. Mr. Langlois provided information about the two packages of 75% lean ground beef he had purchased on September 3 for the Labor Day cookout. The meat had been purchased at the Stop & Shop Grocery Store located on Willow Street in Manchester. Upon arriving home from the store Mr. Langlois made 24 patties; all but six were consumed at the family barbeque held on September 4. These six were put in his freezer where they remained along with a bulk portion of the beef not used to make hamburgers. At the request of the NHDHHS Mr. Langlois packed the frozen leftover meat with ice packs in a cooler and delivered the seven packages to the NHDHHS for microbiologic testing on September 21.
That same day City of Manchester Department of Health Environmental Health Specialist Phil Alexakos, MPH, REHS, visited the Stop & Shop. Mr. Alexakos findings are summarized in a report, “E. coli O157:H7 Case Associated with Ground Beef Purchased at a Manchester Food Service Establishment.” The report notes:
The establishment keeps logs of their cleaning and sanitizing of the grinder. The grinder is used only for grinding beef. There are, however, two different methods for providing 75% lean ground beef. Most common is regrinding “chub” or already ground beef which comes on large tubes. The other method is to grind “trim” or pieces of cut beef (scraps of whole muscle material). There is no differentiation of “chub” versus “trim” on packaging. In addition, it was reported that because this was a holiday weekend it was more likely that trim ground beef was used, but there is no certainty.”
Mr. Alexakos further noted that he observed an employee grinding meat and then leaving the prep area without changing his cloth gloves or washing his hands as observed. Furthermore, the grind room hand sink was not easily accessible. Both were noted as food safety critical violations on the Food Service Establishment Inspection Report. A follow-up inspection was scheduled for September 23.
Preliminary results of the meat testing were reported to NHDHHS epidemiologists on September 22. E. coli O157:H7 had been found in all seven samples submitted. The next day testing was complete and the presence of E. coli O157:H7 in the ground beef was confirmed. The NHDHHS notified the USDA who agreed to investigate the feasibility of conducting a product traceback and possible recall. City of Manchester Department of Health officials persuaded Stop & Shop management to issue a Public Health Advisory which was released at 9:00 pm on September 23. The advisory recommended that customers who purchased ground beef at the Stop & Shop on September 3 should not use the product and return it to the store for a full refund.
The NHDHHS Public Health Laboratory conducted pulsed field gel electrophoresis subtyping on isolates obtained from meat culture and culture of Hercules’ stool specimen. On October 3, 2005 NDHHS microbiologist Krista V. Marschner emailed NDHHS epidemiologist, Elizabeth Gagnon, informing her that 6 meat isolates had been run and that all 6 were a PFGE match to Hercules when using the XBA restriction enzyme. Three of the 6 meat isolates matched when BLN restriction enzyme was used. The patterns were uploaded to PulseNet, a national database maintained at the Centers for Disease Control and Prevention (CDC) in Atlanta. The XBA pattern was assigned pattern identification number EXHX01.3010. The matching BLN pattern obtained from 3 meat samples and Hercules’ isolate were assigned identification number EXHX26.1038. The differing BLN pattern was one band different and assigned identification number EXHX26.1039. Elizabeth Gagnon explained the one band difference as a very small genetic mutation in some of the colonies, saying that:
it is safe to say that he [Hercules] acquired the infection from the contaminated meatÔæñand even still from a regulatory perspective we don’t want E. coli O157:H7 in any ground beef regardless of whether it matched to the case, right?”
Stop & Shop did not keep records of what trim was ground and added to its tubed meat to produce the product that Mr. Langlois purchased on September 3. As a consequence, the USDA could not conduct a thorough traceback to determine the initial or “upstream” source of the contaminated meat. No additional cases of E. coli O157:H7 were reported in the Manchester area and the investigation was closed in October 2005