The European Centre for Disease Prevention and Control (ECDC) and the European Food Safety Authority (EFSA) have issued a Technical Report on the recent STEC/VTEC outbreak in Germany.

Citation: Shiga toxin/verotoxin-producing Escherichia coli in humans, food and animals in the EU/EEA, with special reference to the German outbreak strain STEC O104. Stockholm: ECDC; 2011.

This Report summarizes the epidemiological data on the outbreak of Shiga toxin/verotoxin-producing Escherichia coli (STEC/VTEC) with special reference to the strain STEC O104:H4 which has now been isolated as the causative agent for the largest outbreak of hemolytic uremic syndrome (HUS) ever reported.

The Report discusses the fact that E. coli easily and frequently exchanges genetic information with related bacteria around it, such as Salmonella spp., Shigella spp., and other E. coli strains, through horizontal gene transfer mechanisms. Therefore, E. coli strains may exhibit confusing characteristics that have been acquired from a wide variety of other pathogenic species.

The German outbreak strain possesses an unusual combination of virulence factors of STEC/VTEC and enteroaggregative E. coli (EAggEC). This combination is very rare and has been previously described in strains of serotype O111:H2 involved in an earlier outbreak of HUS in children in France.

The Report acknowledges that cattle (ruminants) are the primary natural reservoir of STEC/VTEC, particularly for STEC O157. Fields for growing leafy vegetables and other produce can be contaminated with STEC directly by cattle or by indirect means, such as contaminated water, aerosols and dust from livestock production and feeding facilities, as well as other human activities such as landfills and wastewater treatment sites. Wildlife may also play a role in dispersal of pathogens from these sources to fields used for vegetable production. Another source of contamination can be organic fertilizer (manure, municipal sludge) and fecally contaminated water.

The Technical Report is posted below.