Campylobacter jejuni Infection on Poultry Farms and its Effect on Poultry Meat Contamination during Slaughtering.

In 1984, we monitored 4 ranches with a total of 24 houses (15,000-20,000 birds/house) for 3 consecutive generations (January-August). On epidemiologic grounds, infection of birds did not originate at the hatcheries or the central water and feed. Considering all lots of birds, the infection rate increased from 2.3% by the 10th day to 9.5, 29.7, 47.9, 65.7, 78.6 and 81.8% by the 20th, 30th, 40th, 45th, 50th day and at slaughter times, respectively. Transmission from one generation of chickens to the next via the old litter is suspected, but not proven microbiologically. A 5-log reduction of Campylobacter jejuni was shown in experimentally inoculated litters stored at 17 and 30°C for 6 d and 8°C for 11 d. The houses remained empty for 9-29 d before being filled with new chicks. Carrier flocks contaminated the slaughterhouse equipment to such an extent that negative flocks processed afterwards resulted in contaminated meat. Lack of effective sanitation at the end of the day contributed to the contamination of meat from Campylobacter -free birds processed the next day. Feather picker drip water was positive 94% of the sampling times at levels of log 3.4 (1.0-4.7). Scalding temperatures did not affect the level of contamination in the finished products (P>0.2). An ELISA based on heat-stable antigens was adapted for the detection of circulating antibodies. Of 56 broilers aged 50 to 68 d, only 2 (3.5%) 68 d old with log 5.4 C. jejuni /g of feces were considered as positive. Birds considered negative harbored C jejuni in their ceca at levels of log 2.0 to 5.4/g of feces. Five out of 6 (83%) 18 month-old hens were considered as positive. Yet, none of these birds were found carrying C. jejuni in their feathers or ceca.