EHEC outbreak: update 9
The outbreak remains primarily centred in Germany, and investigations continue into the nature of the unusual Escherichia coli bacteria serotype and its source.
Haemolytic uraemic syndrome (HUS)
As of 5 June at 15:00 CET, Germany had reported 630 HUS cases (including 15 fatalities); 3 more than the previous day. 70% of cases were in females and 89% in adults aged 20 years or older, with the highest attack rates per 100 000 population in the group aged 20–49 years. Case-onset dates ranged from 1 May to 2 June.
Enterohaemorrhagic Escherichia coli (EHEC)
As of 5 June at 15:00 CET, 1601 cases of EHEC infection (without HUS) had been reported in Germany (6 fatal):65 more than the previous day. 62% of cases were in females and 88% in adults aged 20 years or older. Case onset dates ranged from 1 May to 3 June.
Because of notification and transmission delays, the observed decrease in notified case numbers since 23 May cannot be considered evidence for decreasing outbreak activity.
As of 5 June at 18:00 CET, 12 other European countries had reported a total of 31 HUS cases (1 fatal) and 73 EHEC cases (none fatal):
In addition, the Centers for Disease Control and Prevention (CDC) in Atlanta, United States of America had previously published information on 2 HUS cases in the United States linked to this outbreak.
All but one of the above HUS and EHEC cases were in people who had travelled to or lived in 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, or more precisely a strain of enteroaggregative verocytotoxin-producing E. coli (EAggEC VTEC) O104:H4.
Investigations continue into the source of the outbreak.
EHEC and HUS have exclusive notification categories, so case numbers should not overlap. The figures in any rapidly evolving outbreak, however, are provisional and subject to change for a variety of reasons.