Campylobacter loads range between 6.4 and 9.0 log CFU/g in Japanese broiler ceca. A LAMP assay directly detects C. jejuni/C. coli in broiler ceca within 90 min. Sensitivity and specificity for LAMP were equal to conventional culture methods. Prevalence in the broiler flocks was correlated with the food poisoning frequency. High broiler prevalence is a crucial risk factor in food poisoning in humans.