|Agenda Item 4.2 a)
FAO/WHO Global Forum of Food Safety Regulators
Country report on the Swedish experience relating to the control of Salmonella in the national herd, with specific focus on the salmonella policy related to poultry production, and the results regarding Salmonella prevalence and human salmonellosis incidence
by the Ministry of Agriculture, Food and Fisheries (Sweden)
Country Report proposed by Sweden
Sweden has achieved an efficient control of Salmonella, despite the industrialisation of animal production. The prevalence of Salmonella in feed, live animals and animal products produced in Sweden is very low. In beef and pork it is less than 0.05% and less than 0.1% in poultry at slaughter. This unique position has been achieved by a national control strategy from feed to food, which was initiated more than 40 years ago. A severe domestic Salmonella epidemic during 1953, involving more than 9000 people of which a few died, demonstrated the need for a more comprehensive control programme.
Sweden´s Salmonella control programme for live animals, eggs and meat was approved by Commission Decision 95/50/EC.
The overall aim of the Swedish Salmonella control programme is that animals sent for slaughter shall be virtually free from Salmonella, which ensures that animal products for human consumtion will be free from Salmonella. The strategies to reach this aim are:
Salmonella infection in any animal species is compulsoriy notifiable, irrespective of serotype. All primary isolates are characterized by sero- and phagetyping and tested for antibiotic resistence.
As the frequency of Salmonella isolation in Swedish poultry is very low, most of today´s measures are of preventive nature. Four factors are of major importance to maintain the favourable situation:
An extensive sampling programme continuosly monitors the Salmonella situation (see table 1). In addition to the sampling at flock level, samples are collected at all poultry slaughterhouses to monitor the end product. Sampling strategies are outlined in the Swedish Salmonella control programme approved by the EU.
Measures in case of Salmonella infection
If Salmonella is isolated from a poultry flock an official veterinarian immediately places restricions on the whole farm. An investigation to trace the source of the infection or any spread of the infection is carried out and official samples are collected. The Salmonella infected flock is destroyed irrespective of serotype and the empty poultry house is thoroughly cleaned and disinfected under supervision of the official veterinarian. Environmental samples are collected after disinfection and have to be negative before restrictions are lifted and new birds are allowed into the house. Since 1995, eggs from Salmonella infected flocks are not allowed for direct human consumption. Eggs from flocks infected with a non-invasive serotype may be used after pasteurisation.
Vaccination of poultry against salmonellosis is not allowed in Sweden.
No cases of Salmonella have been notified in breeders.
During the last 10 years, the Salmonella situation in layers has improved considerably. On average six positive farms have been identified annually between 1995-2000. The dominating serotype has been S.Livingstone which accounts for about 67% of the cases in the 1990s. The total number of herds infected with S.Enteritidis is limited to seven farms. This supports the fact that Sweden has not been envolved in the world wide spread of this serotype in the beginning of the 1990s. In 2000 S. Livingstone was isolated in 3 flocks and S. Yoruba in one flock.
The situation in broilers is very favourable and has improved considerably since the 1970s. In 1995-2000, less than five infected flocks have been detected annually. In 2000 the identified serotypes were S.Havana, S. Senftenberg and S. Mbandaka.
Salmonella infection in humans is notifiable.
During the last three decades different serotypes of Salmonella have increased in the intensive animal production in several countries. For example, the evolution of the S. Enteritidis pandemic which began in the 1980s and reached its maximum in 1992, led to increased foodborne illness in many countries. The outbreaks were associated with consumption of poultry and eggs or products thereof. However, due to the Swedish Salmonella control programme, these serotypes have never spread in the animal population and a unique position with an extremely low Salmonella prevalence in both live animals and animal products has been achieved.
As Swedish red and white table meat and eggs are virutally free from Salmonella, the risk of contracting salmonellosis in Sweden is small. Since many years approximately only 10-15% of all notified human cases of salmonellosis have been domestically acquierd. Since 1980 the annual incidence (cases per 100 000 inhabitants) of notified domestic Salmonella cases has varied between 3 and 14.
Table 1. Mandatory Salmonella sampling scheme in poultry. Total number of sampling occasions and (frequency of sampling occasions) in different categories of poultry.
a Extended sampling compared to the zoonosis directive (92/117/EEC)