Swiss federal veterinary office risk assessments:: Advantages and limitations of the qualitative method

The Swiss Federal Veterinary Office (SFVO) applies risk analysis methods in the fields of animal disease control and food safety. Analysis results are used to formulate import regulations for animals and goods, to check the effectiveness of control measures, and to set up monitoring programmes for animal diseases and food contamination. The assessment of the potential health risks to the population from consuming milk and dairy products contaminated with zoonotic agents is used to demonstrate the steps and the advantages of a qualitative risk assessment. The probability of contamination occurring in raw milk, retail milk, and 12 milk products was investigated. The products posing the greatest risk were raw milk and fresh and soft cheeses whereas the risk from pasteurised milk, cream, butter, and hard cheese was seen to be negligible. Based on these results, the first risk-based monitoring of milk products was introduced in Switzerland in 2002. The initial phase of a risk analysis is a qualitative process. Often, while the risk network is being established, it is realised that the required data are unavailable or that data quality is insufficient. (qualitative evaluation of expert opinion is easier than quantitative evaluation. However, assigning risks to qualitative categories is done subjectively and there is no standardised method. Usually the information provided by qualitative assessments is adequate for risk managers for decision making. Management measures in public health are often 'yes' or `no' decisions. Risk communication between risk managers and stakeholders is simplified when the results of a qualitative assessment are available.