During 2002, 593 culture-confirmed cases of Salmonella infection (12.1 per 100,000 population) were reported. This represents a 14% decrease from the 693 cases reported in 2001 and a 6% decrease from the median annual number of cases reported from 1996 to 2001 (median, 629 cases; range, 601 to 693) (Figure 2). Four serotypes, S. Typhimurium (148 cases), S. Enteritidis (109 cases), S. Newport (56 cases), and S. Heidelberg (34 cases), accounted for 59% of cases reported in 2002. Twenty-five percent of case patients were less than 10 years of age. Twenty-three percent of case patients were hospitalized for their infection.
Six persons died 1 to 32 days after their specimen collection dates; isolates from these case-patients included one S. Adelaide and one S. Tennessee isolated from blood and two S. Newport, one S. Typhimurium, and one isolate of unknown serotype from stool. At least four case-patients who died had serious underlying medical conditions (liver disease, colon cancer, thalassemia, and leukemia, respectively) prior to their Salmonella infection. One case-patient died of cardiac arrest 1 day after discharge from the hospital where he was being treated for Salmonella infection. One case-patient had a positive stool specimen collected during surgery for ruptured diverticula; she died from complications resulting from the surgery 20 days later.
Six outbreaks of salmonellosis were identified in 2002; five were foodborne, and one involved person-toperson transmission. Three foodborne outbreaks occurred in restaurants. In April, two patrons of a buffet-style Chinese restaurant became ill with S. Enteritidis infection; the vehicle was not confirmed, but chicken was suspected. In July, five patrons and five employees of a restaurant were culture-positive for S. Newport; ten additional patrons were identified as having symptoms compatible with salmonellosis. The investigation revealed several food preparation practices that could have resulted in cross-contamination from raw to ready-to-eat foods, and that employees worked while ill with gastrointestinal symptoms. The third outbreak of salmonellosis in a restaurant occurred in November. Fourteen patrons had confirmed S. Typhimurium infection, and five additional patrons had compatible symptoms. Ten employees also tested positive for S. Typhimurium, 40% of whom reported not having any recent gastrointestinal symptoms. Transmission to patrons occurred over a 2-week period. Multiple foods acted as vehicles. Numerous deficiencies in food-holding temperatures, food preparation, and sanitation procedures were identified; infected food workers also could have played an important role in transmission of Salmonella to patrons. The initial vehicle that introduced Salmonella into the kitchen was not identified.
Two food-borne outbreaks occurred in settings other than restaurants. In August and September, four cases of S. Newport associated with a multistate outbreak were identified in Minnesota. Tomatoes were identified as the vehicle. A S. Enteritidis outbreak in October, which was associated with a gathering in a private home, resulted in five culture-confirmed cases and 13 additional cases of compatible illness. Consumption of fried rice containing eggs was associated with illness.
One person-to-person outbreak of S. Oranienburg infections was identified in a home child daycare setting. This outbreak resulted in three culture confirmed cases among attendees and their family members.
Routine interviews of Minnesota residents with salmonellosis contributed to the detection of outbreaks in Texas and Florida. Eight S. Enteritidis cases reported in Minnesota from March through July were associated with a large outbreak at a conference hotel in Texas. One S. Javiana case was identified as part of an outbreak during the Transplant Olympics held in Florida in June.
- For up to date information see>> Salmonellosis (Salmonella)
- Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2002