Shigella infection (shigellosis) is an intestinal disease caused by a family of bacteria known as shigella. The main sign of shigella infection is diarrhoea, which often is bloody. It may be mistaken for food poisoning.

Shigella can be passed through direct contact with the bacteria in faeces (stool, or “poo”). For example, this can happen in a child care setting when staff members don’t wash their hands well enough after changing nappies. Shigella bacteria also can be passed in contaminated food, or by drinking or swimming in contaminated water. Shigella is becoming increasingly found in men who have sex with men (MSM), where there may be oral-anal contact.

Signs and symptoms of shigella infection usually begin a day or two after contact with shigella, but may take up to a week to develop. Signs and symptoms may include:

  • Diarrhoea (often containing blood or mucus)
  • Abdominal pain or cramps
  • Fever

Although some people have no symptoms after they’ve been infected with shigella, their faeces may still be contagious for up to a few weeks.

In people with normal, strong immune systems, shigella infection usually clears up without complications in 5-7 days, although it may take some weeks before your bowel habits return to normal. However, for people who have a weakened immune system, such as some people living with HIV, a course of antibiotics may be needed. Your doctor will need to examine you and send a sample of your stool for analysis, to confirm the shigella, since there are many things that might cause diarrhoea. 

However, some shigella bacteria have become drug resistant. There is currently an outbreak of drug-resistant shigella in London in the MSM community. So if you are gay, bisexual or a man who has sex with men (MSM), or if you are a person living with HIV, get checked out for shigella if you have persistent diarrhoea, stomach cramps and a fever.
More information about shigella in MSM can be found on the THT website. There is also a downloadable leaflet from THT – click here