72 cases of Salmonella infection found in Lowndes County
Kelli Hernandez of the Valdosta Daily Times reports:
On Sept. 13, Bob Manning from the Georgia Public Health Laboratory (GPHL) contacted the Notifiable Diseases Epidemiology Section (NDES) of the South Georgia Health District (SGHD) that the lab had received eight Salmonella Montevideo isolates from South Georgia Medical Center between Aug. 28 to Sept. 5, according to a report filed by the Department of Human Resources Division of Public Health.
On average, Lowndes County reports approximately five cases per year of Salmonella Montevideo infection. Due to the drastic increase in cases, an investigation was initiated to determine whether or not the cases represented an outbreak in the area and if a common source could be identified amongst the patients, according to the report.
A questionnaire was developed to evaluate sources of possible exposure including animal contact, water sources, grocery stores, restaurants and specific food, according to the report.
Following the investigation and interviewing patients infected, 72 cases of Salmonella Montevideo infections with indistinguishable patterns were reported with the onset of gastrointestinal illness between Aug. 21 and Nov. 15, and investigators were able to determine the outbreak strain, according to the report.
Of the 72 cases, 19 patients were hospitalized and no deaths were reported, according to the report.
Following interviews of 52 of the 72 patients, the investigation revealed that a common fast food restaurant in Valdosta was the source of the outbreak strain. Of those interviewed, 82 percent reported that they had most likely eaten at the restaurant in the seven days before symptoms began, and the risk of being infected rose 1.5 times for those who had eaten at the restaurant.
On Oct. 6, Tad Williams, Environmental Health director for the South Georgia Health District, was notified by investigators that the fast food restaurant Arby’s was considered a possible source for the outbreak. Leslie Golden, Lowndes County Environmental Health specialist, inspected the restaurant and found no major violations as investigators continued interviews with patients, according to the report.
Interviews continued to point toward the common restaurant as the source. On Oct. 19, Williams, along with Outbreak Coordinator for NDES Cindy Burnett, Dr. Petra Wiersma with the Center for Disease Control and Prevention, and Andy Johnson and Leslie Golden of the Lowndes County Environmental Health Department met with the district manager and manager at the restaurant. The meeting included discussions regarding sources of food served, food preparation, cleaning of equipment and employee health and hygiene, according to the report.
During that visit, 10 swab samples were taken from surfaces in the restaurant and delivered to GPHL and tested for Salmonella.
Normally, the decision to release information to the public concerning an outbreak is decided after collaboration between the state and local health director, according to Public Health liaison Courtney Sheeley.
“Typically what we like to do is complete the investigation in its entirety,” Sheeley said. “If you release information in the middle of the investigation it may or may not be accurate, and at that time, we didn’t have a confirmed source.”
Sheeley added that though the particular restaurant had been identified as a possible common source Oct. 6, that report did not point to a specific piece of equipment, which necessitated the continuation of the investigation.
“Initially it looked like a waterborne outbreak,” Williams said.
Williams added that if investigators could not isolate the equipment or area contaminated after the restaurant been identified as the source of the outbreak, the facility would have been closed. However, since the slicer was later identified as the source and it could be isolated and removed, the facility was not closed and the information was not publicized.
Investigators found that the restaurant had been closed for remodeling and reopened on Aug. 18, 2006, and was utilizing a brand new meat slicer following the reopening. Nineteen days after the restaurant was identified as the possible source of the outbreak, on Oct. 25, GPHL reported that one of the swab samples collected from the new meat slicer was positive for the Salmonella outbreak strain and the slicer was immediately removed from service. All food items that may have been in contact with the slicer were thrown away and additional food items were collected for testing, according to the report.
Thirty-one additional samples were taken from the restaurant that same day. Though the new slicer had been cleaned and sanitized, Salmonella was still detected on the blade cover.
According to restaurant staff, the equipment was cleaned several times a day and was disassembled and sanitized each night. The cause of the problem was determined to be a faulty piece on the equipment, which according to the manufacturer, should have been sealed with silicone. The piece was not sealed as it should have been when it was inspected by investigators, according to the report.
The report’s discussion concluded that though the initial cause of the salmonella was not discovered, salmonella persisted between the blade cover and handle due to lack of a seal in spite of frequent cleaning just after the restaurant reopened.
“Once we get the information from the state that identifies a common source, at that point we would go to the common source,” Williams said. “Once we were there we, along with state folks, collected samples. As soon as they confirmed that the problem was with the slicer, we immediately removed the slicer out of service as well as any food that had been sliced on that particular slicer and no other areas in the facility was contaminated.”
Control measures taken by the SGHD included removal of the slicer and the discarding of all potentially contaminated foods. The restaurant returned the slicer to the manufacturer, who has issued a lookout to other restaurants with the same product to inspect the handle. The restaurant chain is also conducting an internal investigation into the possible source of salmonella contamination of the blade cover, according to the report.
No exposure to the outbreak strain was identified after the slicer was removed from the restaurant Oct. 25, according to the report.
Typically, people infected with Salmonella will experience diarrhea, fever and abdominal cramps 12-72 hours after infection. The illness normally lasts four to seven days and most patients recover without treatment, though elderly and infants can experience severe illness, according to the report.
This outbreak could also have included some person-to-person exposure, which Sheeley added could be controlled if patients continued to practice good hand washing techniques and washed their hands frequently.