How can micro-organisms contaminate poultry and eggs and what are the diseases they cause?

Spain

Food such as poultry and eggs can become contaminated with micro-organisms that cause food poisoning at any stage of the ‘farm to fork’ food chain. Animals can be infected through contaminated feed, living areas and other infected animals. They can also be transmitted vertically (parent to offspring) through eggs.

One of the most widespread infections in poultry and chicken eggs is Salmonella. An animal infected with Salmonella excretes them and can thereby cross-infect any other healthy animal with which it comes into contact - at the farm, to and from market and in the slaughterhouse. Infections are mostly the result of inadequate cooking and/or cross contamination, exacerbated by poor handling/storage techniques of food and occasionally also by infected animals. The most common symptoms of a Salmonella infection are general malaise, diarrhoea, high fever, vomiting, severe abdominal pain and the possible development of septicaemia or peritonitis.

Another widespread poultry infection comes from Campylobacter. These bacteria can survive for three months in frozen chickens. Infections are usually the result of eating inadequately cooked or recontaminated chicken or turkey meat. Campylobacter infection often occurs five to seven days after eating infected food. This is because it takes this long for the bacteria to multiply enormously in the gut and cause disease. Symptoms are general malaise, followed by severe diarrhoea and abdominal pain. Vomiting is rare. It can easily be mistaken for appendicitis because of the severe pain and fever. Blood and mucus may be excreted in the faeces.

Some people, particularly children, pregnant women, the elderly and persons with an impaired immune system are more vulnerable to these infections than others. It is therefore especially important for these groups not to eat raw eggs or uncooked foods and to ensure high hygienic standards.