Shigellosis is caused by Shigella bacteria, which includes several species pathogenic to man, with humans as the main reservoir.

Transmission occurs by the oral-faecal route, either directly person to person or spread via contaminated food or water. The infective dose may be very low. More recently, sexual transmission among men that have sex with men has become a more common cause of outbreaks in several countries.

The clinical picture may therefore vary between a mild enteric infection (watery, self-limiting diarrhoea) and very serious symptoms (high fever, dysentery, , intestinal perforation, kidney failure). Reactive joint inflammation and urethritis can follow the enteric symptoms. Antibiotic therapy and fluid replacement are effective. Shigellosis is a leading cause of childhood deaths in developing countries.

Prevention measures are based on good general food and waste hygiene and proper hand-washing.