FSS finds O157 and non-O157 strains of E. coli in Errington Cheese
An investigation into the E. coli O157 outbreak which was closed earlier this month after 20 illnesses has also been re-opened after two more infections were reported.
The multi-agency Incident Management Team (IMT) chaired by Health Protection Scotland concluded the outbreak was linked to Dunsyre Blue, produced by Errington Cheese.
Of the 22 confirmed cases, the IMT said 19 had eaten blue cheese prior to becoming ill. A total of 15 are known to have eaten Dunsyre Blue while others cannot be certain about the brand.
Angus cases link
Dr Alison Smith-Palmer, chair of the IMT, said it has considered all information available and continue to believe Dunsyre Blue remains the most likely cause of the outbreak.
“During investigations of this nature, the organism causing the outbreak is not always identified from the implicated food as the food consumed by cases is often not available for testing as illness can occur weeks after the food has been eaten.
"In addition, not all those who have eaten an implicated product will become ill because the organism is not always evenly distributed throughout the product."
She added the IMT has been reconvened and will meet on a regular basis to review and consider information as it becomes available to protect public health.
NHS Tayside Health Protection Team and Angus Council are investigating cases of E. coli O157 infection affecting children in Angus.
The IMT said initial information suggests there may be a link to the national outbreak.
FSS: Our decisions have been evidence-based
FSS said E. coli O157 and non-O157 have been detected in different batches of Dunsyre Blue and Lanark White.
“Potentially harmful strains of E. coli and the shiga toxin (stx) genes that can cause illness in humans have been found in a number of different batches of different cheeses produced by Errington Cheese.
“This means that FSS is not satisfied that the controls and production methods used by the business are producing safe food.
“Furthermore, the reliance on a limited number of negative test results as evidence that the food is safe provides insufficient assurance, as it is clear that multiple samples across different cheese batches have had positive results.”
FSS testing examples
- Batch F15 Dunsyre Blue: STEC has been cultured and isolated from a sample of this batch. This sample has been confirmed as a non-O157 E. coli (STEC). Nine further samples were taken from this batch, and have been found to contain the stx2 gene and one for the stx1 gene (all nine samples are considered presumptive positive for STEC), FSS is awaiting further confirmatory testing. This product has not been placed on the market.
- Batch G14 Lanark White: E. coli O157 has been cultured and isolated from a sample taken from this batch. This isolate has not been shown to contain the stx genes and is undergoing further analysis. Stx gene negative strains of E. coli O157 have been isolated from cases of human illness consistent with E. coli O157 infection
Errington Cheese has voluntary recalled cheese twice and FSS has made two further recalls – on 10 and 14 September.
The updated information affects all batch codes and pack sizes of Dunsyre Blue, Dunsyre Baby Lanark Blue, Lanark White, Maisie’s Kebbuck and Cora Linn purchased until 14 September.
Errington Cheese supplies to wholesalers who supply to retail and catering establishments. The products are provided to specialist cheese shops, delicatessens, hotels and restaurants.
Outbreak link and timeline
The firm’s Dunsyre Blue cheese had been linked to an outbreak of E. coli O157 (VTEC) which sickened 20 people and one child died.
Errington Cheese said its own testing has shown cheese is safe to eat.
FSS said comments by Errington Cheese that E. coli O157 has not been found in its cheese were ‘inaccurate’.
Some samples submitted by South Lanarkshire Council (SLC) have tested positive for E. coli O157 and for a non-O157 strain.
Further samples have tested positive for shiga toxin (stx) genes and “presumptive positive” for shiga toxin producing E. coli (STEC).
FSS said analysis of samples by SLC had been carried out using accredited methods in official laboratories.
Last week, FSS ordered the withdrawal of batch G14 of Lanark White as South Lanarkshire Council tests were positive for E. coli O157 but no illnesses were reported.
Errington Cheese said when it was told of the presumptive E. coli O157 result it consulted experts in dairy microbiology.
“The experts told us they were confused and concerned by the testing methodology adopted by the laboratory. We have given careful consideration to this and to the fact that the cheese has been on the market for three weeks now with absolutely no reported incidence of illness.”
