The German Federal Institute for Risk Assessment (BfR) says the statistics reveal that, last year, for the first time, incidents of the disease caused by the foodborne pathogen fell below that of those cause by Campylobacter germs.
Salmonella are to be found in 29 per cent of the large-scale German laying hen flocks. In Scandinavian countries this figure is less than one per cent, while in some eastern European countries it is 65 per cent or higher, the agency noted. The EU average is about 31 per cent.
The statistics are the preliminary results of a pilot study commissioned by the European Commission in the 25 EU member states in a bid to assess the problem and then deal with it.
In Germany fewer and fewer people have contracted Salmonella infections since 1992. Last year 52,000 cases were reported in Germany, still a figure that needs to be brought down, the risk assessment agency stated.
"The number of Salmonella infections is falling overall," said BfR president Andreas Hensel. "The results of the pilot study do, however, confirm that we can't afford to rest on our laurels. The prevalence of Salmonella in laying hens must be reduced further in order to afford consumers even better protection."
Salmonella infection goes hand in hand with symptoms like diarrhoea, nausea, vomiting and headaches, sometimes with fever as well. Mostly the illness pursues a mild course but there are also serious, typhoidal cases. The most frequent source of infection are contaminated foods, in particular eggs and dishes made from them.
Infected laying hens transmit the Salmonella into and onto the eggs.
The Germany study is part of a one-year pilot study meant to establish how many laying hen flocks are affected.
With positive test results in 29 percent of the large-scale laying hen flocks, Germany is below the European average of 31 percent.
The study results were recorded by the official control authorities of the federal states for a total of 563 selected flocks based on the examination of faeces and dust samples from each flock.
Salmonella findings from the environment of the hens were also included in the assessment.
They show that Salmonella type S. Enteritidis in the most predominant form of the pathogen amongst laying hens. Another human pathogen, the S. Typhimurium variant, was detected in two per cent of the flocks.
"Following initial assessment there seems to be a link between Salmonella exposure, size of farm and form of husbandry," the BfR stated. "Larger farms with more than 3,000 laying hens in cages were more frequently affected than those in barn, perchery or free-range systems."
Studies back in the 1990s had already indicated that S. Enteritidis could be a problem with laying hens.
This led to the introduction of a compulsory vaccination for laying hens in Germany. The steady drop in reported cases of salmonellosis in human beings by around one-third since 2001 alone was seen as a success of this vaccination, the BfR stated.
In future, flocks will be regularly examined by official bodies and targeted measures taken in the case of positive test results, the BfR stated.
"One option involves imposing constraints on the use of the eggs," the agency stated. "By means of this and other measures, the risk to consumers is to be further reduced. At the same time, this responds to the provision of the European Commission envisaging a 30 per cent reduction in Germany of the number of flocks contaminated with Salmonella by the end of 2008."
The German study has been evaluated by the European Food Safety Authority (EFSA). The final figures will be available in the autumn.
In Germany the data were collected by the official control bodies. They were then examined and evaluated by the BfR.