Cryptosporidium and Giardia - HE1212

About these infections and how to prevent them

What are Cryptosporidium (say ‘crip-toe-spor-idium’) and Giardia (say ‘gee-ah-dee-ah’)?

Cryptosporidium and Giardia are parasites found in the gut of infected people and animals.

People with Cryptosporidium infections (called cryptosporidiosis) or Giardia infections (called giardiasis) usually get diarrhoea (runny poo). Some people, such as the very young or very old, can get very sick from cryptosporidium or giardia infections, and the symptoms can last for a few weeks.  

How do you get infected?

People or animals with these infections pass the parasites on in their faeces (poo).  Without good hygiene and handwashing, the parasites can get onto food and surfaces and into water and soil.  

The parasites can live in the environment for long periods, especially in lakes, rivers, streams and roof water. There is no way of telling by taste, sight or smell if soil, food, water or a surface has Cryptosporidium or Giardia parasites.

• You get infected when you swallow the parasites, for example by:
  drinking contaminated water
• having contact with faeces (poo) from infected people or animals
• swimming or playing in contaminated ‘recreational water’, such as rivers, lakes, swimming pools and spa pools
• eating contaminated food, especially raw or undercooked food
• touching contaminated surfaces such as toys, bathroom taps, door handles, and nappy change tables and then touching your mouth
• drinking raw (unpasteurised) milk or eating raw milk products.

Travelling overseas can increase the risk of getting these infections, especially to countries with unsafe drinking water and inadequate food hygiene practices.

Illness: Symptoms and timeframes

Cryptosporidium and Giardia infections cause similar symptoms. You may have some or all of the following symptoms.

• Foul-smelling or watery diarrhoea
• Stomach pain or cramps
• Lack of appetite
• Weight loss
• Bloating
• Nausea and vomiting
• Slight fever
• Fatigue (feeling very tired)
• Flatulence (farts)

Cryptosporidium infection symptoms appear 1 to 12 days (usually 7 days) after becoming infected. Symptoms can last for 2 weeks or more. 

For several weeks after your symptoms have gone you may continue to have cryptosporidium parasites in your faeces — you can infect other people during this time.

Giardia infection symptoms appear 3 to 25 days (usually 7 to 10 days) after becoming infected. Symptoms can last for 3 to 4 days, then you feel better, then the symptoms may come back. If you don’t get treatment, this cycle can continue, and you can be infectious for months.

If you have symptoms

If you have symptoms, you should do the following.

• Go to your usual GP, hauora or healthcare provider if your symptoms are severe or last for more than 3 to 4 days. They may ask to test a sample (small amount) of your faeces. Your doctor will give you advice on how to collect the sample and what to do with it.
• Take medicines if your doctor prescribes them. 
• Drink plenty of water while you have diarrhoea or vomiting.
• Go back to your GP, hauora or healthcare provider if you have a child that is ill and drinking much less than usual or showing signs of dehydration (passing less urine (wee) than usual, dry mouth, sunken eyes, or seeming drowsy).
• Go back to your GP, hauora or healthcare provider if your symptoms have not gone away after 7 days, you have a fever or bloody diarrhoea.
• Stay away from school, early learning services or work until 48 hours (2 days) after the symptoms have gone. 
• Do not go swimming in a pool or spa pool or share bathwater if you have diarrhoea. You need to wait at least 2 weeks after you last had diarrhoea.
• Avoid preparing food for other people. If you must do so, wash and dry your hands well first.
• Follow the advice of your doctor or local public health service.

Cryptosporidiosis and giardiasis are both notifiable diseases – this means your GP, hauora or healthcare provider will inform your local public health service if you become infected. The public health service may contact you to find out how you were infected. This helps prevent other people from getting sick.

Preventing these diseases

To prevent getting cryptosporidium and giardia infections or passing them on, you 
can do the following.

Wash your hands

Wash your hands thoroughly and often using clean, warm water and soap for at least 20 seconds, cleaning between fingers and under fingernails, rinsing well and drying on a clean dry towel or paper towel. To reduce the spread of these and other parasites, it is important you do this:  

• Before eating and preparing food
• After handling raw meat
• After going to the toilet, changing nappies or helping others use the bathroom
• After caring for people who are ill
• After contact with pets or farm animals
• After gardening.

Alcohol-based hand sanitiser does not kill the cryptosporidium parasite or stop the spread 
but washing hands with soap and water does.

Suitable cleaning

Clean hard surfaces and objects (including toys) that may have become contaminated with a suitable cleaning solution, such as water and detergent. Then use a sanitizing solution that contains 3% hydrogen peroxide and leave for at least 20 minutes. Note: there is no disinfectant that is guaranteed to be fully effective against Cryptosporidium, however hydrogen peroxide is more effective than sodium hypochlorite (plain bleach).

Follow safe drinking water practices

• Avoid drinking water that has not been treated — including water from lakes, rivers, streams or rainwater from a roof collection. 
• If you have to drink untreated water from lakes, rivers, streams or rainwater from a roof collection, it should be made safe first by bringing it to the boil, disinfecting it or putting it through an appropriate treatment unit.
• If you are planning on going camping or tramping in a rural area, consider where you will get your drinking water from and whether it will be safe. It may be safest to take your own bottled water with you.

For more information on how to make your drinking-water safe visit taumataarowai.govt.nz. 

When tramping and camping

• To avoid contaminating our waterways and spreading parasites to others, always use toilets if they are available.
• If you need to go to the toilet but there isn’t one available, bury your toilet waste and paper. Make sure you bury it at least 15 to 20cm deep and 50 metres (about 70 steps) away from water sources (such as rivers, lakes or springs), tracks and campsites.
• Do not wash your hands directly in a water source. Collect water in a clean container, wash your hands with soap and water and then drain used water into the ground away from the water source.

To discuss your health and treatment options, speak to your usual GP, hauora or healthcare provider. You can also call Healthline free on 0800 611 116. 

For more information on these infections and how to prevent them scan this QR code, visit kidshealth.org.nz or contact your local public health service.

To find the contact details for your local public health service, scan this QR code or visit tewhatuora.govt.nz/publichealthcontacts.

Code: HE1212