Human is the only reservoir "Campylobacter jejuni is a common cause of bacterial gastroenteritis in most pas of the world". Reservoir The bacterium has a broad host range and has been isolated from a range of sources including surface and ground waters, domestic and wild mammals, insects and wild birds. The most prominent source of human infection is consumption of chicken meat (poultry) either directly or through cross-contamination with other food items. The intestines of poultry are easily colonized with campylobacter jejuni. Day old chicks can be colonized with as few as 35 organisms. Pathogenesis :? Infection is acquired by ingestion. The jejunum and ileum are the first sites to become colonized. The organisms are invasive; in well developed infections the mesenteric lymph nodes are enlarged. Clinical features The average incubation period is 3 days with a range of 1-7 days. Abdominal pain and diarrhoea are main symptoms. Severe watery diarrhoea may lead to prostration. Leucocytes are almost always present in the feces and .frank blood may be apparent. Symptoms usually resolve within few day.s. Sequaleae of Campylobacter jejuni infection There are two conditions that may arise 1-2 weeks after the infection. Guillain Barre Syndrome -Guillain Barre syndrome (GBS) a demyelenating disorder resulting in acute neuromuscular paralysis is a serious sequlae of campylobacter jejuni infection. - An estimated one case of GBS occurs for every 1000 cases of campvlobacteriosis. Upto 40% of patients with this syndrome have evidence of recent campylobacter infection. 2) Reiters Syndrome -A reactive (aseptic) ahritis affects 1-2% of patients. - It typically affects the knees, ankles and wrists.