Worldwide there are more than 20 different Campylobacter species. In the industrialised countries Campylobacter jejuni is the second most common cause of intestinal inflammation. The primary reservoirs for the organisms are wild warm blooded animals and farm animals. Campylobacter infections in humans are primarily a result of food contamination, inadequately heated poultry being the primary source of infection. The incubation time is generally between two and seven days. Most infections with Campylobacter jejuni are asymptomatic while symptomatic infections present with typical acute enteritis. Between 12 and 24 hours prior to enteric symptoms sufferers often have prodromal symptoms of headache, myalgia, arthralgia, and tiredness. The most common symptoms are diarrhoea, abdominal pain, fever and tiredness. The infection is generally self limiting although 5 to 10 % of untreated patients may have recurrences. Rare complications of infection are Guillain-Barré-Syndrome, an inflammatory disease of the peripheral nervous system, and reactive arthritis. Campylobacter infection is usually diagnosed by isolating the bacterium from stool or blood samples. The complement fixation test provides a reliable test system for serological testing. In recent years the serological detection of antibodies against Campylobacter jejuni in routine diagnostic applications has increased in relevance. Successful isolation of the organism from stool samples is only possible during a short time window during infection. However reactive arthritis only presents one or two weeks post infection and G-B syndrome usually one to three weeks post infection and consequently ELISAs are a useful serological instrument.