Shigella infection (shigellosis) is an infection of your bowel caused by the bacteria called Shigella. When a person is infected, the Shigella bacteria is in their poo and can easily infect others.
- Shigellosis is not common in New Zealand and most people who get it have recently travelled to less-developed countries or have had contact with someone who has.
- Symptoms usually include watery poos, blood in your poos or tummy pain. The illness can last for up to 2 weeks.
- You may need antibiotics for the treatment of shigellosis. It is also important to drink lots of fluids to prevent dehydration. Older adults and children are most at risk of dehydration.
- Good hygiene like careful handwashing, cooking food properly and drinking clean water are important to prevent you from getting shigellosis.
- People with symptoms should not go to school, daycare or their workplace until 48 hours after they have had no symptoms.
How is shigellosis spread?
You get infected when you swallow the Shigella bacteria. This can happen when you:
- eat food that has been contaminated or poorly handled – flies and other insects like cockroaches can transfer the bacteria to food
- contact with poo from a person that has shigellosis – this can happen if hands are not washed properly after going to the toilet or changing nappies
- drink untreated water – animals can contaminate water collected from roofs, bores, creeks, lakes and streams
- swimming in contaminated waterways
- some types of sexual activity (oral–anal sex).
You can infect other people while the Shigella bacteria is in your body and poo. This is usually for a month from when diarrhoea starts.
Who is most at risk of shigellosis?
Shigellosis is not common in New Zealand. People who have shigellosis have recently travelled to less-developed countries and been exposed to the bacteria there.
Shigellosis can affect anyone. However, people who are most at risk of getting the infection are:
- people with poor immunity
- older adults
- young children.
What are the symptoms of shigellosis?
The symptoms of shigellosis include:
- watery, runny poos
- blood in your poos with or without mucous
- nausea (feeling sick) and vomiting (being sick)
- stomach pain.
These symptoms usually start 1 to 3 days after coming in contact with Shigella bacteria and can last up to 2 weeks. Some people do not have any symptoms even though they are infected.
How is shigellosis diagnosed?
Shigellosis infection is diagnosed by testing the presence of Shigella bacteria in your poo. You will need to provide a poo sample for the test if your doctor thinks you have shigellosis.
How is shigellosis be treated?
See your doctor if you think you may have shigellosis. Your doctor may prescribe antibiotics. You need to rest and drink plenty of water to prevent dehydration. This is especially important for children who are more likely to get dehydrated.
How long do I need to take off work or school with shigellosis?
Anyone with diarrhoea or vomiting should not go to work, school or daycare until they have had no symptoms for 2 days.
Food handlers, healthcare workers, childcare workers and children in childcare will need clearance from a doctor or nurse before they are allowed to return to work or childcare. Clearance usually involves providing a poo sample to check for Shigella bacteria.
People who have had close contact with a person with shigellosis may also need clearance before they go to work or childcare too depending on their risk factors (such as their job and exposure to the Shigella bacteria).
How can shigellosis be prevented?
There is no vaccine to prevent shigellosis.
To avoid getting shigellosis:
- regularly wash your hands with soap and dry them thoroughly, especially after contact with animals, going to the toilet, changing a nappy, caring for a sick person and before preparing or eating food
- keep food covered
- cook food well – this will kill the bacteria
- wash raw fruit and vegetables before eating
- only drink water that is treated and known to be safe – if you are not sure if the water is safe boil it first and if you have your own water supply, protect it from animal and bird poo and treat the water.
If travelling overseas (especially to less developed countries):
- be careful around the food and water you consume
- avoid uncooked foods
- avoid fruit and vegetables unless you are able to peel them yourself and then wash your hands
- drink bottled or boiled water.
To avoid spreading shigellosis:
- regularly wash and dry your hands thoroughly
- do not go swimming in pools until you have had no symptoms for 2 weeks
- do not prepare food for others until you have had no symptoms for 48 hours (2 days)
- use household chlorine bleach mixed with water to disinfect areas where vomit and poo have spilled and clean surfaces and items you use often.