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 Aotearoa New Zealand and most people who get it have recently travelled to less-developed countries or have had contact with someone who has.
On this page, you can find the following information:
- How is shigellosis spread?
- Who is most at risk of getting shigellosis?
- What are the symptoms of shigellosis?
- How is shigellosis diagnosed?
- How is shigellosis treated?
- How long do I need to take off work or school?
- How can shigellosis be prevented?
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
- have 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
- swim in contaminated waterways
- engage in 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.
People who have shigellosis have recently travelled to less-developed countries and been exposed to the bacteria there. Shigellosis can affect anyone. However you are at higher risk of getting the infection if you:
- have poor immunity
- are an older adult
- are a young child.
The symptoms of shigellosis include:
- watery, runny poos sometimes with blood or mucous
- nausea (feeling sick) and vomiting (being sick)
- stomach pain.
These symptoms usually start 1–3 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.
Shigellosis infection is diagnosed by testing for 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.
Contact your doctor if you or one of your family members have bloody diarrhoea (blood in runny poo) or severe stomach cramping or tenderness, especially if you also have a fever (high temperature) or feel very sick.
Your doctor may prescribe antibiotics. You need to rest and drink plenty of water to prevent dehydration. This is especially important for tamariki/children as they are more likely to get dehydrated.
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).
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.