An outbreak of salmonella in England and Northern Ireland, which has affected more than 60 people and resulted in one death, is being linked to duck eggs.
The outbreak is being investigated jointly by the Health Protection Agency and the Food Standards Agency. Both agencies have warned consumers about the need to thoroughly cook duck eggs.
Salmonella has been effectively eliminated from hen’s eggs in the UK since the introduction of the British Lion scheme in 1998. This has been confirmed by a number of independent surveys.
A report from the Advisory Committee for the Microbiological Safety of Food in 2001 acknowledged the success of the British Lion vaccination programme in tackling salmonella in eggs and in 2004 the Food Standards Agency found no salmonella inside 28,000 UK-produced eggs tested. In 2006 the status of UK egg production as among the safest in the world was confirmed by a EU salmonella zoonoses survey.
Only this year figures released by Defra and the European Union showed that the United Kingdom had done much better than other leading European egg producing countries in eradicating salmonella from its laying flocks.
The Food Standards Agency now says it has issued warnings about duck eggs to both consumers and caterers.
The warning follows an outbreak of salmonella typhimurium DT8. The agency says that from 1 January 2010 to date, 63 cases of salmonella typhimurium DT8 infection have been reported in the United Kingdom.
"Two cases are known to have resulted in people being hospitalised and one death has been reported (although at present it is uncertain whether the death is directly related to the salmonella infection)," said the agency in a prepared statement.
"Evidence from investigations carried out by the HPA and FSA supports a link between the consumption of duck eggs and this outbreak."
The FSA statement read, "Duck eggs may occasionally be contaminated with salmonella both on their shells or, more rarely, internally. Duck eggs should be cooked thoroughly until both the white and yolk are solid.
If you are cooking a dish containing duck eggs, make sure you cook it until the food is steaming hot all the way through. Good hygiene practices should be followed when handling and storing all eggs, such as washing hands, utensils and preparation surfaces after handling or using eggs."
Dr Dilys Morgan, who is leading the investigation for the Health Protection Agency, said that as soon as the agency first noticed an increase in cases it started detailed investigations using food questionnaires and interviews to find the common cause of illness in the people affected and to identify the source of the outbreak.
The HPA conducted epidemiological and trace back investigations. Detailed food histories were collected from 21 cases during July and August known not to have travelled outside the UK. These revealed that 14 (67 per cent) had eaten duck products; 11 duck eggs, two duck liver pate and one duck meat.
The HPA found that the eggs came from a variety of sources - from local small retailers, farms or at market places. Duck eggs contaminated with the outbreak strain were collected from a patient’s home and investigations by the Food Standards Agency also revealed evidence of salmonella typhimurium DT8 further up the duck egg supply chain.
"It became clear from our investigations that the increase was related to the consumption of duck products, mainly eggs," said Dr Morgan. "It is important that consumers and caterers are aware that all eggs, including duck eggs, may occasionally be contaminated with salmonella and follow advice provided by the Food Standards Agency in order to reduce the risk of infection. Eggs should be cooked thoroughly and good hygiene practices, such as washing hands, utensils and kitchen surfaces should be followed after handling or using duck eggs."
The HPA put the number of confirmed cases at 66 rather than 63. "Of the reported cases two are known to have been hospitalised, one of whom has died. Cases are mainly adults with an average age of 46 years, and most are men (61 per cent). Cases have been referred from Northern Ireland and most regions in England, with predominance in the South East and North West," said the HPA in a statement.
A similar outbreak of the same type of salmonella was recently recorded in Ireland. This was also linked to duck eggs.