Just over one in four chickens reared in Ireland is infected with the salmonella bacterium, a survey by the European Food Safety Authority (EFSA) has revealed.
At 27.6 per cent, the Irish incidence of salmonella is higher than the European average of 23.7 per cent, according to the survey of over 7,000 chicken flocks. Salmonella is a principal cause of foodborne illnesses, ranging from stomach bugs to typhoid.
The risk to human health comes from under-cooking or cross-contamination of other foods. However, the survey says the two principal strains of salmonella linked to foodborne illnesses are not found in Ireland. While Irish chickens have the highest levels of Salmonella Mbandaka in Europe, this strain rarely causes food poisoning.
"This is actually a good news story for Ireland, because the types of salmonella we have here are not too bad," commented Prof Patrick Wall of UCD, who is chairman of the EFSA. "You couldn't say Salmonella Mbandaka doesn't infect humans, but it isn't one of the two strains that is responsible for most illnesses."
Two types of the bug, Salmonella Enteriditis and Salmonella Typhimurium, accounted for about 300 of the 418 cases of salmonella infections reported in Ireland in 2004, the most recent year for which figures are available. The Salmonella Mbandaka strain was linked to two cases. However, Prof Wall said there was no cause for complacency, as up to 60 per cent of chickens are infected with another infectious micro-organism, campylobacter.
This too can be eradicated through thorough cooking and good kitchen hygiene. In addition, up to 90 per cent of chicken in the catering trade and some retail chicken is imported to Ireland, often from countries where virulent forms of salmonella are present. The only European country where chickens are not infected with salmonella is Sweden, which has aggressively tackled the disease by heat-treating feed and eliminating disease-carrying pests.
The highest rates are in Hungary, where over 68 per cent of birds are infected, and Spain, with 41 per cent infection. According to Prof Wall, an opportunity exists for the Irish poultry industry on both sides of the Border to market itself as free of the major strains of salmonella. However, Northern Ireland is lumped in with the rest of Britain, which has disease-causing strains, for the purpose of international classification.
"The safest chicken to eat is fresh Irish chicken, but all chicken is safe if you cook it properly," said Prof Wall. Every year, about 69 million broiler chickens are reared and killed for their meat in the Republic. Nearly all of these are reared in enclosed sheds that can contain 10,000 - 20,000 birds, with no access to outdoors.