Summary

• Intestinal infection with flagellated protozoan parasite.
• Transmission is via the faecal-oral route. Personal hygiene is key to prevention.
• Symptoms vary from asymptomatic passage of cysts to acute self-limiting diarrhoea or chronic diarrhoea. Growth retardation in children has been well described.
• Diagnosis is by detection of cysts or trophozoites in a stool sample.
• Metronidazole or tinidazole is recommended as first-line treatment.