Preliminary Observations on the Occurrence of Campylobacter jejuni at Four California Chicken Ranches

During a 3-month period from April to July, 1983, three Campylobacter jejuni survey studies were done at four chicken ranches in Northern California. In Survey 1, 29 of 200 (14.5%) total cloacal swab and dropping samples collected from the 20 occupied houses on the four ranches were positive for C. jejuni . Positive samples were from two of the four ranches. On one of these ranches, both occupied houses were positive. However, on the other ranch, only one of six houses was positive. Follow- up feed, water, litter and dropping samples were collected from three houses on this latter ranch during Survey 2. Again, positive samples were from only one house with 26 of 30 (86.7%) droppings positive for C. jejuni and 3 of 20 (15%) water samples positive. No feed or litter samples were positive. During Survey 3, cloacal swabs or bird dropping samples were collected from two houses on each of three ranches at approximately weekly intervals from the time of arrival of new flocks of chickens. All six houses ultimately became positive. The first positive samples were collected from one house when chickens in that house were 12 d old. This house had contained C. jejuni -positive chickens during Survey 1, had old litter, and had not been very thoroughly cleaned and disinfected. First positive samples in each of the other five houses were collected when chickens were between 40 and 46 d old. Two of these houses had previously been positive for C. jejuni but had old litter replaced with new and had been thoroughly cleaned and disinfected. The three other houses had been negative for C. jejuni during Survey 1. Two of these houses had new litter and had been well cleaned. The other house contained old litter and had not been well cleaned. When each house became positive, virtually all samples from that house were positive within a week indicating that C. jejuni likely spreads rapidly among birds in the house.