These are the current figures from the World Health Organization for the outbreak. Enterohaemorrhagic Escherichia coli (EHEC) and haemolytic uraemic syndrome (HUS) have exclusive notification categories, so case numbers should not overlap.
The figures in any rapidly evolving outbreak are provisional, however, and subject to change for a variety of reasons.
- As of 02 June at 15:00 CET, Germany had reported 520 cases of HUS, including 11 fatalalities: 50 more than the previous day. 70% of the cases were in females and 89% in adults aged 20 years or older.
- As of 02 June 15:00 CET, 1213 cases of EHEC infections (without HUS) had been reported in Germany, 6 of them fatal: 149 more than the previous day. Of those cases, 61% were in females, and 88% in adults aged 20 years or older. Case onset dates for EHEC ranged from 1 to 30 May.
- As of 03 June 18:00 CET, 11 other European countries (see table) had reported a total of 31 HUS (1 fatal) and 70 EHEC cases (0 fatal).
Country | HUS | EHEC |
Austria | 0 | 2 |
Czech Republic | 0 | 1 |
Denmark | 7 | 10 |
France | 0 | 10 |
Netherlands | 4 | 4 |
Norway | 0 | 1 |
Poland | 1 | 0 |
Spain | 1 | 0 |
Sweden | 15 | 31 |
Switzerland | 0 | 3 |
United Kingdom | 3 | 8 |
In addition, the Centers for Disease Control and Prevention (CDC) in Atlanta, United States of America had previously published information on two cases of HUS in the United States that were linked to this outbreak.
All but 1 of the above HUS and EHEC patients had travelled to or from Germany during the incubation period for infection, typically 3–4 days after exposure (range 2–10 days). An increasing number of cases is laboratory confirmed as EHEC serotype O104:H4.
Follow WHO updates for HUS and EHEC here.
Follow WHO updates for HUS and EHEC here.
The number of HUS cases per 100,000 inhabitants in the most affected states was 5.5 for Hamburg, 5.1 for Schleswig-Holstein, 3.3 for Bremen and 1.8 for Mecklenburg-Western Pomerania. A link to Northern Germany has been found in most cases from other federal states.
As part of the investigation of the EHEC/HUS outbreak, RKI is performing further epidemiological studies, including case control studies, online surveys and investigation of conspicuous clusters (see Epidemiologisches Bulletin 22/2011). Preliminary results are available for two of these studies.
In a case control study, 46 patients with HUS or EHEC infection from Bremen, Hamburg and Lübeck were questioned in detail from May 29 to June 2, 2011 on the foods they consumed, including foods not included in a previous case control study performed in Hamburg the results of which were published on May 25, 2011. These cases were compared to 2100 healthy controls matched for age group, sex and region of residence. Lettuce was consumed by 84% of cases, but only 47% of controls. Similarly, 75% of cases but only 50% of controls had consumed cucumbers and consumption of tomatoes was reported by 80% of cases, but only 63% of controls. A total of 95% of cases had consumed at least one of these three vegetables. Statistical analysis showed that the consumption of tomatoes, cucumbers and raw lettuce remain significantly associated with the occurrence of HUS.
Results of an investigation of a cluster of EHEC cases from a Frankfurt business company performed by the local health authority in Frankfurt and the State Health Authority in Hesse (HLPUG) in Dillenburg found that individuals who had eaten from the salad bar in the company cafeteria had a 7-fold increased risk of developing bloody diarrhoea than those who had not. No such association was seen for other foods investigated, such as dessert, fruit and asparagus.
These two unrelated and methodologically distinct studies support results of the previously performed case control study, which were presented on May 26, 2011. Thus from an epidemiological perspective, the consumption of lettuce, tomatoes, and/or cucumbers obtained in Northern Germany must be considered to have the highest relative risk for infection compared to other foods investigated. The dietary recommendations of the BfR will thus be upheld until epidemiological studies or testing of foods suggest other causal factors, the source of the infection is definitively identified or until cases cease to occur.
Since the beginning of May, 2011, a large number of persons have contracted bloody diarrhoea and the haemolytic uremic syndrome (HUS) in Germany. Since the beginning of May, RKI received reports of 520 notified HUS cases, including 11 deaths (as of June 2, 2011, 1500h CET). In the same period, reports of 1213 notified cases of EHEC infection were received. Of these, six have since died.
HUS is a severe, sometimes fatal complication of bacterial infection of the gastrointestinal tract with so-called enterohaemolytic Escherichia coli (EHEC). On average, RKI receives approximately 1000 reports of notified EHEC cases. HUS is characterized by the triad of acute renal failure, haemolytic anaemia and thrombocytopenia. In 2010, two reports of HUS-related deaths were reported to RKI.
EHEC bacteria are transmitted directly or indirectly from animals to humans. Ruminants, in particular cattle, sheep and goats, are considered to be the reservoir. Transmission to humans is via the faecal-oral route, in which the pathogen is transmitted to humans through contact with animal excreta or via contaminated foods or water. Human-to human transmission via the faecal-oral route is also possible.
As a precautionary measure in view of the serious nature of the EHEC/HUS outbreak in May 2011, it is recommended to abstain from eating uncooked vegetables suspected of being associated with the source of the infection (tomatoes, cucumbers and lettuce) and obtained in Northern Germany until the definitive source of the outbreak has been identified. Since a very low number of EHEC bacteria is sufficient to establish infection, transmission is easily possible.
Robert Koch Institute
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