Sequential spread of Campylobacter infection in a multipen broiler house

Generally, colonization with Campylobacter jejuni is first detected in broi lers 2-3 wk after hatching. Once introduced into a dock, this infection spr eads very rapidly. The sources and routes of transmission of C. jejuni in b roilers remain debatable. In this study, the spread of infection was monito red in a commercial multipen broiler house in which birds were contained in discrete groups and sampled sequentially. Colonization was monitored in tw o broiler flocks up to slaughter. Serotyping and fla typing methods were ap plied to differentiate all the C. jejuni strains isolated. In dock 1, colon ization was first detected at 32 days of age in birds located at the rear o f the house. By 40 days, nearly all the birds were infected with the same s train (fla type 1.9). However, at 46 days of age, a second strain (fla type 3.7) was detected in some of the birds. These birds were also located towa rd the rear of the house. In flock 2, infection was detected at 5 wk of age . This infection was once again first detected in birds located at the rear of the house. In this flock, only a single fla type (1.1) was isolated thr oughout. A survey of the broiler house relative to the location of first po int of infection indicated the use of an entrance door unprotected by boot dips. However, securing this door during the second flock study did not pre vent infection.