The European Food Safety Authority (EFSA) has estimated that the overall economic impact of human salmonellosis to the EU economy could be as high as EUR 3 billion a year.
Salmonella remains one of the most common food-borne diseases worldwide and therefore the control of salmonella contamination from food has a high priority within the EU, USA and many other countries. The control of salmonella in Europe started with the first EU Directive in 2001.
There followed a series of regulations that focussed on the measurement and reduction of the prevalence of the “Big 5” salmonella in the EU, namely S. Enteritidis, S. Typhimurium, S. Infantis, S. Virchow and S. Hadar. Of the big 5, S. Enteritidis (SE) and S. Typhimurium (ST) are by far the most important.
In general, SE was associated with eggs and egg products, while ST was mainly associated with meat products.
Therefore the main focus of EU-wide control and monitoring programmes is on reducing the prevalence of Salmonella enterica ssp. enterica serovar enteritidis (S. Enteritidis) and Salmonella enterica ssp. enterica serovar typhimurium (S. Typhimurium). These food-borne zoonotic agents can lead to serious disease in humans (gastroenteritis) despite causing no clinical symptoms in the infected flock. Salmonella bacteria occur worldwide.
In the poultry house, salmonella may be found in standing water, food and feed, feed containers, bedding, equipment, dust and faeces. These are therefore the main areas that are sampled for salmonella under the EU zoonosis monitoring process.
In laying hens, infection with S. Enteritidis and S. Typhimurium does not generally lead to disease symptoms. This is why the salmonella monitoring and control programs in the EU apply to all flocks of more than 250 birds, Germany practises compulsory vaccination against both serovars mentioned above (S. Enteritidis and S. Typhimurium). Other countries generally have either a voluntary, or compulsory vaccination policy, with Denmark and the other Scandinavian countries preferring a slaughter control methods. A strong link has been established between the introduction of the EU control/monitoring methods in poultry, and the reduction of prevalence of salmonellosis, especially SE in humans. Vaccination plays a key role in reduction of salmonella prevalence in poultry.
For this purpose, IDT Biologika Animal Health offers an oral vaccine for administration via drinking water. Vaccinated birds are protected against both S. Enteritidis and S Typhimurium at least 63 and 60 weeks after the 3rd vaccination respectively. This type of protection is known as horizontal protection as it protects across the whole flock.
The parent birds (breeders) are also vaccinated to help prevent any disease passing from one generation of birds, to the next. This is known as vertical protection and this “top down” type of control has helped successfully reduce the prevalence of salmonella in the EU’s layer and broiler flocks.
The key to salmonella control is
1. Good management
2. Good hygiene and biosecurity
These three elements feature strongly in any successful salmonella control program.
The salmonella monitoring and control programs in the European poultry industry since 2001 can be seen as a real success, helping to reduce the burden of food-borne disease to the population of the EU.