Cost-effectiveness analysis of the Danish Salmonella control strategy

Abstract

The mandatory national Danish Salmonella Control Program in swine has been in place since 1995. The over all goal for the current program is to reduce the salmonella prevalence in pork from 1.7% in 2001 to a maximum of 1.2% in 2006. In order to achieve this, the Danish swine industry decided to conduct a cost-effectiveness study in order to achieve the optimal salmonella reduction at the lowest possible costs. The study showed that further pre-harvest initiatives using the currently known measures can not reduce the salmonella prevalence in Danish pork sufficiently. At the present stage of the Danish Salmonella Control Program only intensified focus on slaughterhouse measures, like decontamination and intensified hygiene, can reduce the prevalence of Salmonella in Danish pork sufficiently to attain the goal of 1.2%. Introduction The mandatory national Danish Salmonella Control Program in swine has been in place since 1995, and operates at all stages of the production chain (Mousing et al. 1997, Nielsen et al. 2001). During the first 5 years of the program the strategy was mainly focused on salmonella control in the primary production, and to a less degree on slaughterhouse related factors. Since 2001 an increasing focus has been placed on evaluating the importance of each step in the salmonella control program in order to achieve a reduced level of Salmonella in Danish pork, and consequently in the number of pork related human salmonellosis cases. The Salmonella control program for swine has reduced the pork related number of human salmonellosis cases from 22/100,000 inhabitants in 1993 to 3/100,000 in 2003 (Anon 2004). The annual costs of the program were 4.5 million Euro in 2003. In total, the costs of the salmonella program have been close to 95 million Euro since its initiation in 1995. Assuming that the number of human cases had remained at the pre-control level if the salmonella-program had not been implemented, the program has reduced the occurrence of human salmonellosis in Denmark by approximately 1,000 registered cases in 2002 (Nielsen et Korsgaard 2003). The overall goal for the current Danish salmonella control program is to reduce the salmonella prevalence in pork from 1.7% in 2001 to a maximum of 1.2% in 2006. In order to achieve this, a new strategy needed to be developed an implemented. The Danish swine industry covers the majority of the expenses of the control program, and the industry consequently decided to conduct a cost-effectiveness study in order to achieve the optimal salmonella reduction at the lowest possible costs. Materials and Methods Salmonella-reducing measures along the entire production chain were evaluated based on the following criteria: practical experience, literature, salmonella-reducing effect, costs, how easy or difficult the measure is to implement under practical conditions, and finally estimated consumer perception. After a first phase evaluation of possible salmonella reducing measures, 9 measures/ initiatives were selected for the final cost-effectiveness analyses. Each measure was scored with respect to: effect, easiness to implement, expenses over 15 years, 1-year costs, and ability to attain the goal of 1.2% salmonella in pork by 2006. Results of approximately 16000 pooled swab samples from the Danish Salmonella surveillance of carcasses were used for the calculations. At each slaughterhouse, five randomly selected carcasses per slaughter day are swabbed at three defined areas (the hind leg near the tail, the sternum, and the jowl. The three areas are swabbed with the same gauze pad, and the pads from the five carcasses sampled on the same day are analyzed as one pooled sample (Sorensen et al. 2001). The samples originated from 22 slaughterhouses associated with the Danish Bacon and Meat Council. The samples covered the period from January 1 2001 to June 1 2004. For each sample all 5 carcasses were identified by the herd register number. For these herds, serological samples from the Danish serological surveillance were obtained from the Danish