The BfR evaluated and assessed 2,540 study results on the presence of Listeria monocytogenes in three product groups: smoked and gravad fish, soft and semi-soft cheese, and heat-treated meat products.
They concluded that people such as pregnant women and those with immunodeficiencies should avoid eating the products as a precaution.
Samples were tested by the authorities in the federal state from 1 January 2010 to 31 December 2011 as part of an EU-wide baseline study.
The BfR highlighted the fact that products exceeding the microbiological limits fixed by legislation for Listeria monocytogenes within the sell-by date are not marketable.
Business operators must ensure that only foods are placed on the market which do not exceed these criteria when handled and stored correctly and if limits are exceeded, there is a risk of consumers contracting a listeria infection, said the agency.
Salmonella and campylobacter
In contrast, food contaminated with salmonella, are on the decrease and despite a decrease in the animal population, campylobacteriosis continued to be the most common foodborne infectious disease in humans in 2011.
Future studies will show whether the positive trend for campylobacter is a permanent improvement or not, said the BfR.
The proportion of fresh beef and pork samples contaminated with salmonella was reduced to below 1% in 2011. Slightly higher detection rates were found in minced meat, wild boar and poultry.
Frequency of detection of campylobacter in broilers and broiler meat fell compared to previous years: in 2011, 25.1% of animals slaughtered and 31.6% of broiler meat samples were contaminated with campylobacter.
However, for other zoonotic pathogens such as VTEC and Yersinia enterocolitica no decrease was observed.
“No reason to give the all clear”
"Although this decrease in salmonella contamination is quite favourable, it is no reason to give the all-clear. For consumers, raw meet continues to be a source of microbiological hazards and necessitates careful handling of such foods,“ said BfR President Professor Dr Andreas Hensel.
"Food business operators must take suitable measures to ensure that only foods are placed on the market for which the food safety criteria for listeria are not exceeded if they are handled and stored correctly,“ he added.
BfR cited an EHEC outbreak due to contaminated sprouts in 2011 as an example of plant-based foods being contaminated with pathogens, showing a lack of knowledge with regard to new and unusual safety hazards still poses one of the main challenges.