Control of Salmonella enteritidis in Sweden

The Swedish control of Salmonella, with special reference to Salmonella enteritidis, in poultry is described. The control is directed at all serotypes of Salmonella and imported grandparent chickens are controlled, which is considered to be the main reason why Sweden so far is not found to be involved in the worldwide spread of different phagetypes of S. enteritidis However, this spread has initiated a more stringent control of Salmonella in layers as earlier existed in broilers. Since 1990, 90% of the layer flocks are voluntarily tested for Salmonella before slaughter by bacteriological examination of pooled faecal samples. If S. enteritidis is isolated the flock is destroyed. This test and in addition two similar tests during the production are mandatory as of January 1st, 1994. The voluntary Salmonella control programme has also been extended to all of the layer parents and hatcheries since 1991. Only heat-treated feed is given to all layer chickens during the rearing period and its use is becoming gradually more common also during the production period. Since 1987, four layer flocks have been found to be infected by S. enteritidis phagetype 4 and one flock with phagetype 6. During 1970–1984, 90% of all flocks of broilers were voluntarily tested bacteriologically for Salmonella before slaughter and since 1984 such a control is mandatory to all flocks. As a result of this and other controls, S. enteritidis has not been isolated from broilers since 1972. on a governmental regulation from 1961, introduced as a result of a large Salmonella epidemic in 1953, Sweden runs an active, official control of Salmonella (Wierup et al., 1992). The objective of the control is to deliver Salmonella-free food to the consumers. The concept is that animals delivered for slaughter shall be free from Salmonella by applying the following strategies: Prevent contamination of all parts of the production chain. Monitor the production chain at critical control points to detect if Salmonella contamination occurs. Undertake actions necessary to fulfill the objective of the control when Salmonella contamination is detected. control is directed at all serotypes of Salmonella and especially as no Salmonella -infected poultry are allowed to be imported, Sweden is so far not involved in the pandemic spread of S. enteritidis. The actions undertaken and the result of the control, with special reference to S. enteritidis and poultry, is summarized in the following sections of this paper. A summary of the control is also presented in Table 1.