Escherichia Coli O157:H7 2004

Table 1. E. coli O157:H7 Cases by Race and Sex, Indiana, 2004

  2004 2000-2004
Cases Rate* Cases
Total 58 0.93 457
Race
   White 48 0.87 320
   Black 2 0.36 16
   Other 1 0.63 6
   Not Reported 7 - 115
Sex
   Male 20 0.65 197
   Female 38 1.20 258
   Not Reported 0 - 2

*Rate per 100,000 population based on the U.S. Census Bureau’s population data as of July 1, 2004

Escherichia coli O157:H7 infection is a bacterial disease usually transmitted through raw or undercooked foods of animal origin or foods cross-contaminated by animal products or feces. It has commonly been associated with raw or undercooked hamburger, unwashed produce, and unpasteurized juices. Outbreaks have also been attributed to swimming in or drinking untreated surface water. The infection can also be transmitted person to person and is a special concern in the daycare setting. Rarely, patients can develop hemolytic uremic syndrome (HUS) as a result of E. coli O157:H7 infection. Symptoms of this disorder include kidney dysfunction, hemolytic anemia, and platelet loss; HUS can be fatal. Populations at most risk include young children, the elderly, and those with weakened immune systems. Approximately 2-7 percent of E. coli O157:H7 cases will develop HUS.

In 2004, 58 cases of E. coli O157:H7 infection were reported in Indiana, for a rate of less than 1 case per 100,000 population. Figure 1 shows the number of reported cases per year for 2000-2004. Incidence of disease was greatest during the summer months. Figure 2 shows the number of cases per month in Indiana for 2004. As shown in Figure 3, age-specific rates were highest among preschoolers aged 1-4 years (3.19), followed by children aged 5-9 years (2.29), and children aged 10-19 years (1.32). Females (1.20) were more likely to be reported than males (0.65). The rate for whites was higher (0.87) than that for other races (0.63) and blacks (0.36); however, 7 cases (12%) did not report race data.

Although 35 counties reported cases of E. coli O157:H7 only Marion (6) had 5 or more cases with an incidence rate of less than 1 case per 100,000 population.

There was one reported outbreak of E. coli O157:H7 infection in Indiana in 2004. The outbreak occurred at a daycare facility in Lawrence County. Two children tested positive for the organism. Four other children had symptoms compatible with E. coli O157:H7 infection but were not laboratory confirmed. No daycare staff member was symptomatic or confirmed with E. coli O157:H7. No foods were implicated as the source of the outbreak. Due to the young age of both cases, eating habits were limited to infant-type food. The daycare staff members were given recommendations for prevention of future outbreaks including proper hand-washing techniques and excluding ill staff members.

Of the 58 confirmed E. coli O157:H7 cases reported in 2004, 1 case reported developing HUS.

It is recommended that all clinical laboratories routinely screen all stool specimens for sorbitol-negative E. coli strains. Lack of sorbitol fermentation in E. coli bacteria is a biochemical marker for the O157:H7 serotype. The ISDH requests that clinical laboratories submit all E. coli O157:H7 or sorbitol-negative E. coli isolates to the ISDH Laboratories for free confirmation and subtyping services.

You can learn more about Escherichia coli O157:H7 by visiting the following Web site:
http://www.cdc.gov/pulsenet/pathogens/ecoli.html