New studies show: Salmonella problematic in the case of fattening pigs and turkeys, too
In two studies conducted jointly by the Federal Institute for Risk Assessment (BfR) and the control authorities of the federal states, German turkey flocks and fattening pigs were tested for Salmonella. The results: Salmonella was detected in around 10 percent of the fattening turkey flocks examined. In contrast, the breeding turkey flocks were free of Salmonella. Approximately 13 percent of the samples from fattening pigs tested positive for Salmonella. "For the purposes of precautionary consumer protection, the control of Salmonella must, therefore, already begin at the breeding and fattening stages of food-producing animals", commented Professor Dr. Dr. Hensel, President of the Federal Institute for Risk Assessment. The two studies are part of an EU-wide monitoring programme which provides, for the first time, a representative overview of the scale on which turkey flocks and fattening pigs in the EU are contaminated with Salmonella. Based on the results Europe-wide and specific national control programmes for the reduction of the Salmonella contamination in fattening pigs and turkeys are to be set up.
In the turkey study 300 fattening turkey flocks and 98 breeding turkey flocks were examined which had been selected in a representative manner. Five collective faecal samples from each flock were examined for Salmonella. Salmonella was not detected in any of the samples from the breeding turkey flocks. The situation was different in the case of the fattening turkeys. Salmonella was detected in at least one sample from 31 out of the 300 fattening turkey flocks (10.3 percent). The samples were differentiated serologically and then further examined at the National Reference Laboratory for Salmonella within BfR. It identified 12 different Salmonella sub-groups. They included the two most frequent causes of Salmonella infections in man - Salmonella enteritidis and Salmonella typhimurium in fattening turkeys, albeit on a small scale. Salmonella enteritidis was only detected in one flock, Salmonella typhimurium in eight flocks.
In the fattening pig study 2,569 samples of intestinal lymph nodes were examined bacteriologically. Salmonella can be very easily detected in the lymph nodes. The samples of 326 animals (12.7 percent) tested positive for Salmonella. The National Reference Laboratory for Salmonella within BfR differentiated 23 sub-groups and observed that the human pathogenic species Salmonella enteritidis and Salmonella typhimurium also occur in fattening pigs. With 180 isolates (55.2 percent of the Salmonella-positive samples), Salmonella typhimurium was the most frequently detected whereas Salmonella enteritidis with 10 isolates (3.1 percent) was detected relatively rarely. The results show that both turkeys and fattening pigs are potential sources of infection for man.
During slaughter the Salmonella from infected animals can migrate to the meat and then constitute an infection risk for the people who consume the meat and meat products. The studies show that the control of Salmonella must already begin during the breeding and fattening of food-producing animals. Hygiene during the slaughter of the animals, the processing of the meat and, last but not least, during the preparation of food is equally important when it comes to avoiding Salmonella infections. As Salmonella is heat-sensitive, meat and meat products should be cooked through as this affords the most effective protection against salmonellosis.
BfR has passed on the results of the studies to the European Food Safety Authority (EFSA). There, they are evaluated together with the data from other Member States of the European Union. Based on these representative data which can be compared between the EU Member States, measures for the control of Salmonella are to be elaborated and co-ordinated.