Campylobacteriosis is an infectious disease caused by bacteria of the genus Campylobacter. Most people who become ill with campylobacteriosis get diarrhea, cramping, abdominal pain, and fever within 2 to 5 days after exposure to the organism. The diarrhea may be bloody and can be accompanied by nausea and vomiting. The illness typically lasts 1 week. Some persons who are infected with Campylobacter don't have any symptoms at all. In persons with compromised immune systems, Campylobacter occasionally spreads to the bloodstream and causes a serious life threatening infection. The Campylobacter organism is actually a group of spiral shaped bacteria that can cause disease in humans and animals. Most human illness is caused by one species, called Campylobacter jejuni, but 1 % of human Campylobacter cases are caused by other species.