The genus, Campylobacter (means curved rods), contains slender spirally curved rod shaped bacteria. They mostly have the shape of an ‘S’. These gained prominence for the first time in the 1970’s as a common cause of human diarrheal disease among children and adults. They occasionally cause systemic infections.They are non- spore forming and motile. 5% oxygen is optimal for their growth. Best growth occurs best at 42oC. Camplobacter jejuni, C. coli, and C. lari causes diarrheal diseases. C. fetus causes extra- intestinal infections. C. sputorum and C. concisus causes abscesses.

Medically, the most important species are Campylobacter jejuni. It is responsible for most of the diarrheal attacks worldwide. The infection is a zoonotic disease, the source being food or animal origin, especially raw milk and raw meat. They are the normal intestinal flora of most animals and birds and are shed in their feces. Also isolated frequently from surface waters. Infection normally occurs by ingestion. The main sites of initial colonization are the ileum and jejunum, slowly spreading down to the colon and rectum. The lymph nodes are invaded resulting in bacteremia.

The incubation period is 1-7 days. The illness starts with fever, abdominal pain and watery diarrhea. Stool contains leukocytes and blood. The disease is self limiting, but the shedding of bacteria through feces continues for weeks after recovery.A severe toxin is produced which interrupts the cell division and thereby not allowing to activate the immune system. In turn the immune system is also invaded.Fluid replacement along with electrolytes are only required generally.  Erythromycin and azithromycin may be prescribed at times for treatment.

Laboratory diagnosis depends on the isolation of the bacteria from the stool. Direct microscopic examination, either by phase contrast or dark field microscopy may show the tumbling movement of the spiral bacteria. Fecal or rectal swabs are taken for culturing.C. coli  causes clinical infection different from that of C. jejuni.  About 3- 5 % of the diarrhea is caused by C. coli . They are commonly seen in healthy pigs. C. jejuni is the most important bacterial cause of diarrheal infections in many developed countries. They are more common than salmonellae and shigella.

In developing countries, C. jejuni is endemic and causes asymptomatic infection in humans, birds and domestic animals. Children are more prone to infection in such cases, whereas, older ones overcome the clinical disease due to the immunity developed against it.
Precautions to prevent the disease from spreading:
1) Proper hygienic condition
2) Good food habits.
3) Meat should be properly cooked before eating.
4) Food should be served warm.
5) Hands should be washed clean before and after touching raw meat.
6) Chopping board, knife and other materials used for handling raw meat should be cleaned properly with soap and hot water
7) Infected people should be isolated
8) Caretakers should not touch others or themselves without proper hand washing
9) The toilets should be disinfected after being used by a diarrheal patient.
10) Infected pets should be handled with care.