| Line 12: |
Line 12: |
| | *Usually asymptomatic infections in chickens and turkeys, but occasional outbreaks of avian hepatitis occur with decreased egg production, loss of condition, haemorrhage and necrosis of liver; phase contrast microscopy demonstrates curved rods in bile; in-feed dihydrostreptomycin sulphate in outbreak | | *Usually asymptomatic infections in chickens and turkeys, but occasional outbreaks of avian hepatitis occur with decreased egg production, loss of condition, haemorrhage and necrosis of liver; phase contrast microscopy demonstrates curved rods in bile; in-feed dihydrostreptomycin sulphate in outbreak |
| | *Implicated in [[Intestines Catarrhal Enteritis - Pathology#Undifferentiated Neonatal Calf Diarrhoea|undifferentiated neonatal calf diarrhoea]], a mixed viral enteritis in calves[[Category:Campylobacter_species]][[Category:Dog]][[Category:Cattle]][[Category:Sheep]] | | *Implicated in [[Intestines Catarrhal Enteritis - Pathology#Undifferentiated Neonatal Calf Diarrhoea|undifferentiated neonatal calf diarrhoea]], a mixed viral enteritis in calves[[Category:Campylobacter_species]][[Category:Dog]][[Category:Cattle]][[Category:Sheep]] |
| | + | |
| | + | * An important enteropathogen of man and a number of animal species. |
| | + | * The largest cause of food-poisoning in the UK. |
| | + | ** Is therefore a public health issue. |
| | + | * Very widely distributed on the farm- carried in the intestinal tract of: |
| | + | ** Cattle |
| | + | ** Sheep |
| | + | ** Dogs |
| | + | ** Chickens |
| | + | ** Wild birds |
| | + | * Widespread distribution on the farm means that it is hyperendemic. |
| | + | ** All animals are regularly exposed to it by the faecal oral route. |
| | + | ** Passive (colostral) protection is helpful while active immunity develops. |
| | + | * There is no regular exposure in the hygienic environment of the human or pet dog. |
| | + | ** These animals are much more susceptible to infection. |
| | + | * The intestinal contents of the broiler chicken may be spread around the abdominal cavity at slaughter. |
| | + | ** Most poultry is moderately or heavily contaminated. |
| | + | *** If frozen chicken is inadequately thawed, bacteria may remain viable in the abdominal cavity. |
| | + | *** Bacteria may be ingested by humans handling the raw meat. |
| | + | |
| | + | ====Pathogenesis==== |
| | + | |
| | + | * Bacteria colonise the gut, attach to and invade the mucosa, and produce toxin. |
| | + | * Causes colitis, characterised by: |
| | + | ** Necrosis of absorptive epithelial cells |
| | + | ** Erosion of the mucosa |
| | + | ** Crypt abscesses |
| | + | ** Infiltration of inflammatory cells into the mucosa. |
| | + | *** Primarily [[Neutrophils - WikiBlood|neutrophils]]. |
| | + | * Functional flagella are important as virulence factors. |
| | + | ** Non-flagellate campylobacter do not colonise in vivo, and are less invasive in vitro. |
| | + | * Diagnosed by laboratory diagnosis. |