New Case Definition
Starting 8 June 2011, European Union (EU) Members States are reporting case according to a new case-definition.
Possible Epidemic Case: Any person who developed in or after 1 May 2011;
Probable Epidemic Case Any possible epidemic case of STEC diarrhea or STEC HUS AND during the exposure period of 14 days before the onset of illness, meeting at least one of the following epidemiological criteria:
Confirmed Epidemic Case Any person meeting the criteria for a possible case, AND Isolation of a STEC strain of serotype O104:H4
OR isolation of a STEC strain of serotype O104 AND fulfilling epidemiological criteria for a probable case. EU Members States are reporting number of probable and confirmed cases and deaths.
Developed by the Robert Koch Institute to be applied to HUS-cases associated with the 2011 Germany outbreak.
HUS Clinical criteria: A clinical picture of acute enteropathogenic HUS is defined by the presence of at least two of the following three criteria:
1. Hemolytic anemia
2. Thrombocytopenia ≤ 150,000 cells/mm3,
3. Renal dysfunction
Laboratory confirmed cases: Positive result in at least one of the following tests:
Detection of Shigatoxin
Indirect (serological) detection
Suspect HUS case: Case with a clinical picture of acute enteropahogenic HUS as assessed by the attending physician, but not formally meeting the clinical criteria (at least two of three) identified above, are classified as suspect cases regardless of laboratory confirmation.
Haemolytic uraemic syndrome (HUS): It is a life-threatening disease characterized by acute renal failure (uraemia), haemolytic anaemia, and a low platelet count (thrombocytopenia). It results from EHEC infection, and it is estimated that up to 10% of EHEC-affected patients may develop HUS. The mortality rate has decreased during the last few years and with appropriate treatment is between the 3% and 5%.
It can cause neurological complications (such as seizure, stroke and coma) in 25% of HUS patients and chronic renal sequelae, usually mild, in around 50% of survivors. EHEC or STEC is a severe strain of E. coli bacterium that is commonly found in the gut of animals, mainly ruminants. EHEC produces toxins, known as verotoxins or Shiga-like toxins because of their similarity to the toxins produced by Shigella dysenteriae. They can cause severe foodborne disease. STEC is transmitted to humans primarily through consumption of contaminated foods, such as raw or undercooked ground meat products and raw milk, contaminated water, direct contact with animals or contact with infected people. Symptoms of disease include abdominal cramps and diarrhoea, which may be bloody. Fever and vomiting may also occur.
Since epidemiological week 23, the number of new HUS and non-HUS STEC cases has declined significantly in the European Union states. Nevertheless, the cumulative number of cases from Germany continues to rise, primarily owing to delays in notification. Investigations conducted by the German authorities indicate that the vehicle of the bacterium responsible for the outbreak, is bean and seed sprouts.
On 24 June, France reported a cluster of 8 cases, all adults (six women and two men) presenting bloody diarrhea; of which seven have developed HUS. E. coli O104:H4 has been confirmed in three patients. Preliminary investigative findings suggest that locally grown sprouts might be involved.
In the Americas Region, a total of nine E. coli O104:H4 STEC cases have been identified, of which six cases are confirmed (five in the United States and one in Canada).
Regional Office for the Americas of the World Health Organization