E. coli O157:H7

Signs and symptoms of infection, after an average incubation of 3 to 4 days, include diarrhea and abdominal cramps. The diarrhea can range from non-bloody to nearly entirely blood. Fever is usually low-grade or absent, unlike most bacterial diarrheal illnesses, sometimes leading clinicians to suspect noninfectious etiologies. Strains of E. coli O157:H7 can produce two types of Shiga toxin or verocytotoxin. These toxins can cause hemolytic uremic syndrome (HUS) in about 6% of patients. Currently, this is the major cause of HUS among children in the United States and Canada.

In August 1994, small cluster of cases of E. coli 0157:H7 was identified by the Department of Health (DOH) Leon County Health Department. Further investigation ultimately found eight confirmed cases from a common source, although none was ever found. Infections with pathogenic serotypes of E. coli have been reportable in Florida since November 1994. In 1995, 44 cases of E. coli O157:H7 infection were reported to DOH County Health Departments. The highest incidence of infection that year was in children 1 to 4 years old (1.38 cases per 100,000) and children 5 to 9 (0.86 cases per 100,000). In all, a total of 585 cases have been reported within the state of Florida, for an average of 59 cases per year.

In 2005, Florida experienced its most recent outbreak of E. coli O157:H7, this time linked to petting zoos in the central Florida area. A total of 29 confirmed cases were linked to this outbreak. Seventeen of these confirmed cases (60%) occurred in children less than 5 years old.

The Bureau of Public Health Laboratory in Jacksonville (Hyperlink: https://www.floridahealth.gov/programs-and-services/public-health-laboratories/locations/index.html) provides typing support for epidemiologic investigations of outbreaks caused by E. coli O157:H7 and can perform whole genome sequencing on isolates to assess for Shiga toxin-producing genes. Providers are encouraged to send all isolates of E. coli O157:H7 or suspected Shiga toxin-producing E. coli isolates to BPHL in Jacksonville for DNA analysis and confirmation as defined in Chapter 64D-3 of the Florida Administrative Code (Hyperlink: https://www.flrules.org/gateway/ChapterHome.asp?Chapter=64d-3) .

Laboratory information is being used for surveillance purposes only to identify Florida-specific patterns and to link with PULSENET, a Centers for Disease Control and Prevention data system that tracks multi-state outbreaks.