Salmonellosis, 2001

During 2001, 693 culture-confirmed cases of Salmonella infection (14.1 per 100,000 population) were reported. This is similar to the number of cases reported since 1996 (601 to 656 cases per year, or 12.1 to 14.2 per 100,000 population) (Figure 1). Four serotypes, S. Typhimurium (200 cases), S. Enteritidis (133 cases), S. Heidelberg (52 cases), and S. Newport (48 cases), accounted for 62% of cases. Twenty-four percent of the case-patients were hospitalized for their infection. Four persons died within 2 weeks of their specimen collection date (two had S. Hadar isolates isolated from blood, one had S. Subspecies II Salamae isolated from stool, and one had S. group B isolated from urine). Twenty-five percent of case-patients were less than 10 years of age. Fifty-eight percent of cases were diagnosed during May through September.

Three food-borne outbreaks of salmonellosis were identified in 2001. One occurred at a hotel banquet facility, and two occurred in restaurants. In April, attendees at a food stylist convention became ill with S. Enteritidis infection after consuming eggs Benedict prepared with unpasteurized shell-eggs. Fifteen convention attendees and three banquet facility workers were culture-positive for S. Enteritidis. The second outbreak took place during July in a restaurant setting. This outbreak resulted in 12 culture-confirmed S. Enteritidis infections among patrons and two culture-confirmed infections among employees of the restaurant. Shell-eggs from Ohio were the most likely vehicle for infection. The third food-borne outbreak of salmonellosis occurred in August. This outbreak occurred at a buffet-style restaurant and resulted in nine culture-confirmed S. Newport infections among patrons. Although no single food vehicle was identified, the investigation revealed ample opportunity for cross-contamination of ready-to-eat foods by raw chicken.

Six non-foodborne outbreaks of salmonellosis also were identified in 2001. One outbreak was due to contact with an animal product; three occurred at child daycare settings; one occurred at a private home; and one occurred at a nursing home. In May, 34 culture-confirmed cases of S. Typhimurium infection were identified in children from two elementary schools and their family members. Children at the two schools dissected owl pellets as part of science club. In one of the schools, the owl pellets were dissected directly on a school cafeteria table. The children did not wash their hands after the science activity, and the table was not cleaned before snacks were served on the same table. Samples collected from owl pellets, fecal matter from the owl that produced the pellets, and frozen chicks used to feed the owl also yielded S. Typhimurium isolates that were identical to the outbreak strain by pulsed-field gel electrophoresis. All three child daycare outbreaks were due to person-to-person transmission. One took place in May, resulting in two S. Oranienburg cases; the other two were investigated in July, resulting in two culture-confirmed S. Montevideo cases in one daycare and three S. Typhimurium cases in the other. An outbreak at a party in a private home resulted in two S. Miami cases in July. The vehicle and mode of transmission were not identified. In August, three S. Newport cases due to person-to-person transmission occurred in a nursing home.

• For up to date information see>> Salmonellosis (Salmonella)
• Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2001