Shigellosis

Shigella bacteria cause a gut infection (gastroenteritis) called shigellosis. It's passed from person to person by swallowing poo which has shigella bacteria in it. It only takes a small number of bacteria for the infection to be passed on. 

It's not common in Aotearoa New Zealand. Most people who get it have recently travelled to a developing country or have had contact with someone who has. There are occasionally outbreaks in early childhood centres here.

You get infected when you swallow the shigella bacteria. This can happen when you:

• have contact with poo from a person who has shigellosis – this can happen if hands are not washed properly after going to the toilet or changing nappies
• touch surfaces or things with shigella bacteria on them, then touch your mouth
• eat food or drink water that has been contaminated
• swim in contaminated water
• have sex with someone who has shigellosis, especially anal sex

Most people who have shigellosis have recently travelled to developing countries and been exposed to the bacteria there. Shigellosis can affect anyone. However you are at higher risk of getting the infection if you:

• are a child under 5 years of age
• have weakened immunity
• are a man who has sex with men – while anyone can get shigellosis from sexual contact with someone with the infection, the risk is generally higher for men who have sex with men, and their sexual networks.

The symptoms of shigellosis include:

• watery, runny poo, sometimes with blood or mucous
• nausea (feeling sick) and vomiting (being sick)
• fever
• tummy pain.

These symptoms usually start 1 to 3 days after swallowing Shigella bacteria. The illness usually lasts 4 to 7 days but can last up to 2 weeks. Shigellosis is usually mild but it can be more serious if you are an older adult, a young child or have a weakened immune system.

The shigella bacteria stays in your poo for 2 weeks after the symptoms have gone away. 

Some people don't have any symptoms even though they are infected. 

Shigellosis is diagnosed by testing for Shigella bacteria in your poo. You will need to provide a poo sample for the test if your healthcare provider thinks you have shigellosis.

Contact your healthcare provider 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. 

You need to rest and drink plenty of water to prevent dehydration. This is especially important for tamariki as they are more likely to get dehydrated.

You may need paracetamol for fever or tummy pain. You should not use medicines to stop diarrhoea or cramps. These make your symptoms worse and can make it harder for your body to get rid of the bacteria.

Some people with severe shigellosis, or a high risk of spreading it to other people because of their work, may need to be treated with an antibiotic. Your healthcare provider will discuss this with you.

Returning to work, school or day care

Anyone with diarrhoea or vomiting should not go to work, school or day care until they have had no symptoms for 2 days.

People in some jobs, and with some types of shigella bacteria, also need to have another poo sample tested to show that the shigella bacteria has gone before they can go back to work or childcare. Your healthcare provider will discuss this with you.

People who have had close contact with a person with shigellosis may also need to provide a poo sample before they go to work or childcare too.

There is no vaccine to prevent shigellosis. 

To avoid getting shigellosis:

• regularly wash your hands with soap and dry them thoroughly, especially after going to the toilet, changing a nappy, caring for a sick person and before preparing or eating food
• 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're not sure if the water is safe, boil it first.

If you're travelling overseas (especially to developing countries)

• Be careful around the food and water you consume.
• Avoid uncooked foods.
• Avoid fruit and vegetables unless you can peel them yourself and then wash your hands.
• Drink bottled or boiled water. 

To avoid spreading shigellosis

• Regularly wash and dry your hands thoroughly.
• Don't go swimming or use hot tubs or spa pools until you have had no symptoms for 2 weeks.
• Don't 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've touched.
• Wait to have sex until 2 weeks after you've recovered. If you do have sex:
  • wash your hands, genitals and anus before and after sexual activity
  • don't have sex if you have diarrhoea (runny poo)
  • use condoms or dental dams during anal and oral sex
  • use soap and warm water to clean any objects used in sexual activity(external link) (eg, sex toys) after use and/or between individuals.