Investigation Update: Outbreak of Shiga toxin-producing E. coli O104 (STEC O104:H4) Infections Associated with Travel to Germany

Updated June 3, 2011

Introduction

CDC is monitoring a large outbreak of Shiga toxin-producing Escherichia coli O104:H4 (STEC O104:H4) infections ongoing in Germany. The responsible strain shares virulence characteristics with enteroaggregative E. coli (EAEC). As of June 2, 2011, case counts confirmed by Germany’s Robert Koch Institute* include 520 patients with hemolytic uremic syndrome (HUS) – a type of kidney failure that is associated with E. coli or STEC infections – and 11 deaths.

In the United States, four suspected cases of STEC O104:H4 infections have been identified in persons who recently traveled to Hamburg, Germany, where they were likely exposed. One case of HUS has been reported in each of three states: Massachusetts, Michigan, and Wisconsin. Additionally, one case of Shiga toxin-positive diarrheal illness is still under investigation. All four cases are pending laboratory confirmation.

CDC is working with state health departments to learn more about these suspected cases and obtain bacterial isolates from them for further characterization. In addition, CDC has alerted state health departments of the ongoing outbreak and requested information about any persons with either HUS or Shiga toxin-positive diarrheal illness, with illness onset during or after travel to Germany since April 1, 2011.

Investigation of the Outbreak

At this time, a specific food has not been confirmed as the source of the infections. Travelers to Germany should be aware that the German public health authorities have recommended against eating raw lettuce, tomatoes or cucumbers, particularly in the northern states of Germany (Hamburg, Bremen, Lower Saxony, and Schleswig Holstein). United States public health authorities currently have no information that any of these foods have been shipped from Europe to the United States. The U.S. Department of Defense has been notified of this outbreak because of the presence of U.S. military bases in Germany; there are no known confirmed cases among U.S. military personnel or their dependents at this time. However, reports indicate two U.S. service members in Germany with diarrheal illness are considered suspect cases.  For travel information related to this outbreak, please view the article on CDC Travelers’ Health Website.

Clinical Features/Signs and Symptoms

The strain of STEC causing these illnesses, STEC O104:H4 is very rare, and CDC is not aware of any confirmed cases of STEC O104:H4 infection ever reported in the United States. Any person who has recently traveled to Germany and has signs or symptoms of STEC infection or HUS should seek medical care and let the medical provider know about the outbreak of STEC infections in Germany and the importance of being tested for STEC. Symptoms of STEC infection include severe stomach cramps, diarrhea (which is often bloody), and vomiting. If there is fever, it usually is not very high. Most people get better within 5–7 days, but some patients go on to develop HUS—usually about a week after the diarrhea starts. Symptoms of HUS include decreased frequency of urination, feeling very tired, and losing pink color to skin and membranes due to anemia.

Key Resources

• Escherichia coli O157:H7 and other Shiga toxin-producing Escherichia coli (STEC)
• CDC E. coli Resources for Clinicians
• CDC Travelers' Health Website - "Outbreak Notice"
• Presentation -“Shiga Toxin-Producing Escherichia Coli Infections: What Clinicians Need to Know”
• MMWR - “Recommendations for Diagnosis of Shiga Toxin–Producing Escherichia coli Infections by Clinical Laboratories” [PDF - 287KB]
• Description of the Steps In a Foodborne Outbreak Investigation
• FoodSafety.gov*
• Robert Koch Institute (Germany)*

CDC's Role in Food Safety

CDC leads federal efforts to gather data on foodborne illnesses, investigate foodborne illnesses and outbreaks, and monitor the effectiveness of prevention and control efforts. CDC is not a food safety regulatory agency but works closely with the food safety regulatory agencies, in particular, with the Food and Drug Administration of the U.S. Department of Health and Human Services and the Food Safety and Inspection Service of the U.S. Department of Agriculture.  CDC also plays a key role in building state and local health department epidemiology, laboratory, and environmental health capacity to support foodborne disease surveillance and outbreak response. Notably, CDC data can be used to help document the effectiveness of regulatory interventions.