Shigella

Bacteria in the Shigella genus cause shigellosis, an intestinal infection. Four main species infect people. Illness commonly causes diarrhoea, fever and stomach pain, and severe cases can produce bloody diarrhoea.

The bacteria spread through faecal contamination of hands, food or water. Because a small dose can cause infection, transmission can occur in households, childcare settings, sexual networks and places with inadequate sanitation. Handwashing, safe water and careful food handling reduce risk.

Rising antimicrobial resistance complicates control. Extensively drug-resistant strains can resist the main medicines used when a severe infection needs treatment. Surveillance therefore tracks both case numbers and the resistance pattern of isolates. Domestic clusters matter because they show that resistant Shigella can circulate within a country rather than appearing only in people who travelled abroad.