Don’t think that because your salad sprouts are organic, grown on your window sill, and supposedly good for you, that they haven’t accumulated many food miles or are safe to eat raw. Compelling evidence published by the European Food Safety Authority yesterday points to fenugreek sprouts as the vector of the E. coli that caused the enormous German outbreak in May and June (more than 3000 cases, with 47 deaths) and a French outbreak at Bègles, near Bordeaux, in June. The only common factors in the outbreaks were genetically identical E. coli O104:H4 – and fenugreek from the same Egyptian source.

Fifteen thousand kilogrammes of organic fenugreek seeds, lot number 48088 (expiry date November 2011), left Egypt by sea in November 2009 in a sealed container. Offloaded at Antwerp, it went to Rotterdam by barge and travelled by road to a German distributor, arriving on 15 December. In February this year, 75 kg went to the sprout producer linked to the German outbreak. Four hundred kilogrammes went to a British seed supplier who in January this year sold 95 kg in 50g packets to a French distributor, who in turn supplied batches of between 5 and 125 packets to more than 200 outlets. Seeds from one packet were sprouted in a jam jar and eaten at an open day at a children's community centre in Bègles on 8 June. The sprouts went into cold carrot and cumin and courgette soups, and on crudités.

E. coli O104:H4 is very virulent. Many victims have developed haemolytic uraemic syndrome (which causes kidney failure) and brain damage. A much greater proportion of the infected have developed these complications than is usual with the classical nasty E. coli, O157. It is quite likely that O104 is hot because it is a hybrid. It has the toxins that make O157 virulent coupled with many genes from enteroaggregative E. coli, a bacterium thought to be a common cause of diarrhoea in children in developing countries. Night soil on the fenugreek?