EPIDEMIOLOGY OF CAMPYLOBACTER SPP AT 2 DUTCH BROILER FARMS

Broiler flocks on two Dutch poultry farms were screened weekly for the presence of campylobacter in fresh caecal droppings during eight cons ecutive production cycles. Hatchery and fresh litter samples were take n at the start of each new cycle. Water, feed, insects, and faeces of domestic animals: present on the farms were also included in the sampl ing. Penner serotyping of isolates was used to identify epidemiologica l factors that contribute to campylobacter colonization in the broiler flocks. Generally, broiler flocks became colonized with campylobacter at about 3-4 weeks of age with isolation percentages of 100 %, and st ayed colonized up to slaughter. A similar pattern of serotypes was fou nd within the various broiler houses on one farm during one production cycle. New flocks generally showed also a new pattern of serotypes. M ost serotypes isolated from the laying hens, pigs, sheep and cattle we re different from those isolated from the broilers at the same time. C ampylobacter serotypes from darkling beetles inside the broiler houses were identical to the ones isolated from the broilers. No campylobact er was isolated from any of the hatchery, water, feed or fresh litter samples. Conclusive evidence of transmission routes was not found, but results certainly point towards horizontal transmission from the envi ronment. Horizontal transmission from one broiler flock to the next on e via a persistent contamination within the broiler house, as well as vertical transmission from breeder flocks via the hatchery to progeny, did not seem to be very likely.