2001 Indiana Report of Infectious Diseases: Salmonellosis

Salmonellosis

Rates presented are per 100,000 population and are based on the 2000 U.S. Census.

	Cases	Incidence Rate
Total	549	9.0
Race-specific cases and rates¹
White	321	6.0
Black	33	6.5
Other²	6	2.4^*
Sex-specific cases and rates³
Female	286	9.2
Male	262	8.8

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, rodents, reptiles, and wild birds, such as ducks and geese.

The incidence of salmonellosis in Indiana in 2001 decreased by 19% from 2000, with 549 cases reported (Figure Sal1), or 9.0 cases per 100,000 population. This incidence is below the previous five-year average of 607 cases. The incidence was greatest during the summer months (Figure Sal2).

Age-specific incidence rates were greatest among infants (48.5) followed by preschoolers (23.0) (Figure Sal3). The sex-specific and race-specific incidence rates show very little difference between sexes and races. There were no outbreaks of salmonellosis reported in Indiana in 2001.

Of those counties that reported 5 or more cases, Dubois County had the highest incidence rate (22.7), followed by Warrick (21.0), Jasper (20.0), and White (19.8) (Figure Sal4). The number of reported cases for Indiana counties can be found in Table Sal1.

There are over 3,000 different Salmonella serotypes that differ in somatic and flagellar antigens. The ISDH requests that clinical laboratories submit all positive Salmonella isolates to the ISDH Laboratories for free confirmation and serotyping. During 2001, serotypes were determined for approximately 96% of the 524 isolates submitted. Figure Sal5 shows the distribution of serotypes from initial and reference specimens submitted to the ISDH Enterics Laboratory. Of the 502 Salmonella isolates of known serotype, 115 (25%) were typhimurium (including 11 that were Copenhagen variant), 98 (20%) were enteritidis, 40 (8%) were newport, 38 (8%) were heidelberg, 29 (6%) were java, and the remaining 182 (36%) were other serotypes.

Figure Sal1: Salmonellosis - Reported Cases by Year, Indiana, 1997-2001

Figure Sal2: Salmonellosis - Reported Cases by Month, Indiana, 2001

Figure Sal3: Salmonellosis - Incidence Rates by Age Group, Indiana, 2001

Figure Sal4: Salmonellosis - Incidence Rates by County, Indiana, 2000

Table Sal1: Salmonellosis - Reported Cases by County, Indiana, 2001

Salmonellosis - Reported Cases by County Indiana, 2001
County	Number of Reported Cases	Incidence Rate per 100,000 Population
Adams	6	17.8^*
Allen	30	9.0
Cass	5	12.2^*
Clark	8	8.3^*
Delaware	7	5.9^*
Dubois	9	22.7^*
Elkhart	15	8.2^*
Grant	5	6.8^*
Greene	5	15.1^*
Hamilton	19	10.4^*
Hancock	5	9.0^*
Howard	8	9.4^*
Jasper	6	20.0^*
Johnson	12	10.4^*
Knox	7	17.8^*
Lake	51	10.5
LaPorte	12	10.9^*
Madison	13	9.7^*
Marion	76	8.8
Monroe	12	10.0^*
Montgomery	6	15.9^*
Porter	18	12.3^*
Ripley	5	18.9^*
St. Joseph	15	5.6^*
Tippecanoe	15	10.1^*
Vanderburgh	22	12.8
Vigo	16	15.1^*
Wabash	5	14.3^*
Warrick	11	21.0^*
Wayne	11	15.5^*
White	5	19.8^*
Source: Indiana State Department of Health Note: Rates based on 2000 U.S. Census population. All other counties had fewer than 5 cases and are not reported to protect case confidentiality. * Rate based on less than 20 cases and should be considered unstable.

Figure Sal5: Human Salmonella Isolates, Indiana, 2000

Footnotes

1 - Race was unknown for 189 of the reported cases.

2 - "Other" includes American Indian/Alaska Native, Asian, Native Hawaiian/Pacific Islander, and multiracial.

3 - Sex was unknown for 1 of the reported cases.

* - Rate based on less than 20 cases and should be considered unstable.