Many species of poultry are often infected with campylobacter, especially Campylobacter jejuni and C col, which as enteric bacteria are well adapted to the host and its intestinal tract. Although extensive colonisation of the birds digestive tract occurs this is not often associated with overt or clinical disease. However, campylobacter is very important as a zoonotic pathogen with C. juni being associated with most cases of human campylobacteriosis. Currently the finger is pointed at poultry as a major source of this cause of human food poisoning

Currently there are 16 species in the genus Campylobacter. Three of the campylobacter (C. jejuni C. coli and C. land are known as thermophilic campylobacter and these three cause the vast majority of the cases of human campylobacteriosis. The campylobacter organism is Gram negative, non-spore can convert into coccold or spherical forms

C. jejuni and C. coli are widely distributed among avian species and especially among wild birds. An intriguing series of outbreaks of human food poisoning occurred in the UK as a result of wild birds pecking the top of milk bottles and drinking and thereby contaminating the milk with campylobacter in poultry production it is considered that large numbers of birds in a confined space facilitates the rapid spread of campylobacter within a flock
Various surveys have shown varying flock prevalences and campylobacter appears to be more
prevalent in the warm summer months
Within a broiler flock the prevalence of campylobacter increases with age and is at its highest at slaughter. The prevalence is often higher in free range flocks, in most situations the majority of isolates from poultry are C. jejuni Horizontal transmission from house to house on a farm is important but other sources of infection
include old litter, contaminated drinking water, other animals (farm, wild and pets), people and farm
vehicles Campylobacter is not usually found in fresh feed or fresh litter insects may act as mechanical vectors and the same strains of campylobacter in a broiler flock have been found in insects caught in the house. Flies are a possible vector of campylobacter
Four legged vein have been implicated as introducers of campylobacter into a poultry house and hence the flock it houses
Wild birds are often infected with non-poultry strains of C. jejuni farm staff can carry campylobacter into poultry houses on their boots and clothing and there are
merits in keeping dedicated clothing in each house for use in that house only
Vertical transmission probably does not occur because young birds are usually free of campylobacter and when the organism does become established it is often of a different strains) to those in the breeder flocks of origin. However, there is some evidence, such as campylobacter DNA in embryos and newly hatched chicks, to suggest that vertical transmission may occur.

Incubation period
The incubation period is typically 2-5 days although infection rarely causes disease. The infectious dose is very low-just a few micro-organis
On poultry farms campylobacter is rarely seen in birds younger than 2-3 weeks of age