More thorough knowledge regarding the spread of Campylobacter at farm level will be established, guiding future implementation of preventive measures. Specific risk factors for introducing Campylobacter in chicken flocks identified by case control studies will be confirmed by molecular work applying genetic methods with high discriminatory power. This enables us to follow the extent and significance of transmission routes, and cost effective actions can be established. The fate through slaughter and proce ssing of those Campylobacter strains infecting live chicken will be explored to obtain more knowledge about the frequency of and extent of cross-contamination. This will aid the implementation of future preventive measures. Results from the action plan ag ainst Campylobacter in broilers will be combined with DNA based typing methods that give discriminatory and reproducible results. This approach enables comparison of human and poultry clones. Methods like Amplified-Fragment Length Polymorphism Genotyping and Pulse Field Gel Electrophoresis will be used.