The latest notice follows a precautionary warning issued last week following two cases of E coli infection in Teeside which were linked to consumption of the cheese. Anyone who had bought the cheese, which is mainly sold in specialist cheese shops, was advised to dispose of it in the usual household waste. It is possible a third case of the infection may also be linked to the cheese.
Further investigations have now confirmed that the contamination of the cheese with E coli O157 is likely to have occurred at source and to have affected cheese from more than one production day. The bacteria in the Teeside cases and the cheese have proved identical. Tests are still going on to try and find out how the cheese became contaminated.
Stocks of the cheese have been withheld from sale since the link was made between the cases and the cheese. However there is concern that people may still have some of the cheese in their fridges which is why it is necessary to reiterate the warning, first issued 21 March, that they should not eat the cheese but throw it away. Retailers and wholesalers who have supplies of the cheese have now been asked to destroy it.
Local public health officials are working closely with the cheese maker so that production can start again as soon as any problems in the production process have been identified and put right.
Two women who ate Cotherstone cheese became ill with E coli O157 infection. Both have since recovered, although one was in hospital for five days. The same strain of bacteria was found in another woman who was ill but who has since recovered. It is thought that she may also have eaten the cheese.
E coli O157 is the bacteria that caused the outbreak in Central Scotland two years ago. More recently it caused a large outbreak in Cumbria, associated with milk and thought to have been caused by a pasteurisation failure. Tests have shown that the molecular fingerprint of the Teeside strain is different from the one involved in the Cumbria outbreak.
E coli O157 is capable of causing very severe disease, including bloody diarrhoea (haemorrhagic colitis) and renal failure (HUS: haemolytic uraemic syndrome). Mortality in outbreaks is usually between four to seven per cent.