*Rate per 100,000 population based on the U.S. Census Bureau’s
Salmonellosis is a bacterial disease usually transmitted through raw or undercooked foods of animal origin or foods cross-contaminated by animal products or feces. It can also be transmitted person to person. Common reservoirs include poultry; swine; cattle; reptiles, such as turtles, snakes, and lizards; and wild birds, such as ducks and geese.
In 2004, there were 527 cases of Salmonellosis reported in Indiana, for a rate of 8.45 per 100,000 population (Table 1). Figure 1 shows the number of reported cases for 2000-2004. The incidence was greatest during the summer months (Figure 2). Figure 3 shows age-specific rates were greatest among infants less than 1 year of age (37.16), followed by preschoolers aged 1-4 years (19.45), and adults aged 60-69 years (9.60). Females (9.50) were more likely to be reported with salmonellosis than males (7.27), and whites (6.42) were more likely to be reported than other races (5.64) or blacks (4.20).
The incidence rates were highest among the following counties reporting five or more cases:
White (44.3), Dubois (29.4), Porter (23.9), Cass (19.8), and Shelby (18.3). Figure 4 shows Indiana counties reporting five or more cases.
There were two outbreaks of salmonellosis reported in Indiana in 2004. In July, 28 people were reported ill after eating at a sports event at Eagle Creek Park in Marion County. Four people tested positive for Salmonella enteritidis. The one food common to all cases reporting a food history was a stuffed tomato dish; however, food sample laboratory test results did not show any definitive source of the salmonella. All food items were prepared by a local catering service at a licensed commissary, which was inspected by local health inspectors. The catering company was given a list of food safety practices and instructed on how to adhere to them in order to prevent future outbreaks.
Another outbreak of salmonellosis was associated with a Porter County restaurant in late October 2004. Thirty-five ill people were reported to the local health department. Eighteen were laboratory confirmed positive for Salmonella type D, and of those, five were hospitalized for various lengths of time. All restaurant employees were asked to submit stool samples for testing. Four employees were positive for Salmonella type D and were immediately removed from work until two consecutive samples, 24 hours apart, were negative. No particular food item was identified. Therefore, illness was likely introduced by an asymptomatic person and transmitted through intermittent shedding in the stool of an employee.
There are over 3,000 different Salmonella serotypes that differ in somatic and flagellar antigens. The Indiana State Department of Health (ISDH) requests that clinical laboratories submit all positive Salmonella isolates to the ISDH Laboratories for free confirmation and serotyping. During 2004, serotypes were determined for approximately 70 percent of the 527 cases identified. Of the 364 isolates of known serotype, 100 (27%) were typhimurium; 87 (24%) were enteriditis; 28 (8%) were Newport; 26 (7%) were Heidelberg; and 123 (34%) were other serotypes.