Human parainfluenza viruses (HPIVs)
Key facts
- Human parainfluenza viruses (HPIVs) are a group of viruses that can cause infection in your upper or lower respiratory tract.
- There are 4 types of HPIVs and each causes different symptoms and illnesses.
- Parainfluenza viruses are spread through coughs and sneezes.
- Young children and people with weakened immune systems have a greater chance of getting complications from HPIVs.
- If you or your child are sick, stay at home and avoid close contact with other people.
What are human parainfluenza viruses (HPIVs)?
Human parainfluenza viruses (HPIVs) are a group of viruses that cause infection in your upper or lower respiratory tract.
Infections can vary in severity. Healthy adults can get mild illness. Older people and those with weak immune systems are more likely to get a severe infection.
In children, HPIVs can cause:
What are the symptoms of parainfluenza?
Parainfluenza symptoms are like those of the common cold. They are:
- fever — a temperature above 38°C
- cough
- swollen or red eyes
- sore throat or laryngitis (a hoarse voice)
- nasal congestion or a runny nose
- decreased appetite
- ear pain
- difficulty breathing — wheezing
- vomiting or diarrhoea
On average, you are infected (when harmful germs enter your body and grow) with an HPIV for 3 to 5 days before your symptoms appear. You are most contagious (during this time you can spread the germs to others) during the early stage of illness.
Children with HPIV can still be infectious 1 to 3 weeks after their symptoms have ended.
CHECK YOUR SYMPTOMS — Use the Symptom Checker and find out if you need to seek medical help.
What causes parainfluenza?
Parainfluenza is caused by 4 different types of parainfluenza virus:
- HPIV-1
- HPIV-2
- HPIV-3
- HPIV-4
The different types of HPIV each cause different symptoms and illnesses.
HPIV-1 and HPIV-2 often cause croup in children. HPIV-3 and HPIV-4 are most often linked with pneumonia and bronchiolitis.
Children tend to get HPIV-1 and HPIV-3 more often than adults.
When should I see my doctor?
If you are having difficulty breathing, call triple zero (000) and ask for an ambulance.
Get medical advice if you are concerned about your symptoms.
You should also see a doctor if your symptoms are getting worse or you have any of the following:
- shortness of breath that makes it difficult to walk or do your usual activities
- chest tightness that lasts for more than 10 minutes
- confusion and difficulty remembering the day, date or names
- inability to keep liquids down due to vomiting
- dehydration — you might be dizzy when standing up
FIND A HEALTH SERVICE — The Service Finder can help you find doctors, pharmacies, hospitals and other health services.
How is parainfluenza diagnosed?
To diagnose an HPIV infection, your doctor will take a swab from your nose or throat. The swab is then sent to a lab for testing.
ASK YOUR DOCTOR — Preparing for an appointment? Use the Question Builder for general tips on what to ask your GP or specialist.
How is parainfluenza treated?
There is no specific treatment for human parainfluenza infections.
Self-care at home
Most HPIV infections can be safely cared for at home. Try to:
- rest
- keep hydrated
- use over-the-counter pain relief medicines as needed
Medicines for parainfluenza
Paracetamol may help to ease your symptoms.
Ibuprofen is an anti-inflammatory medicine. It can be used to relieve pain and fever.
Remember to always follow the manufacturer's instructions when using medicines.
Children under the age of 16 years should not take aspirin. This is because it may cause a serious condition called Reye's syndrome.
Antibiotics do not work against HPIVs because they are viruses.
Should I stay at home?
If you or your child are sick, stay at home. Avoid close contact with other people until you feel better.
Should I keep my child home from school?
Children do not need to be kept home from school if they have threadworms.
Here's a list of recommended exclusion periods for common childhood illnesses, including threadworms.
What are the complications of parainfluenza?
Complications from parainfluenza viruses include:
- bronchiolitis
- bronchitis
- croup
- pneumonia
Young children and people with weakened immune systems are more likely to get complications from HPIVs.
Can parainfluenza be prevented?
Human parainfluenza viruses can easily spread from person to person. However, there are some steps you can take to help protect yourself and your family.
- Wash your hands after sneezing or coughing. Use soap and water and wash for 20 seconds. If you don't have soap and water, use an alcohol-based hand sanitiser.
- Cover your nose and mouth with a tissue or your elbow when you cough or sneeze. Don't use your hands. Dispose of used tissues in a bin straight away.
- Wear a face mask. Masks give you an extra layer of protection against viral illnesses and are strongly recommended in crowded places.
If you or your child are unwell, you should stay home until your symptoms are gone and you feel better. This stops you from passing the virus on to other people.
If someone in your home is sick with a virus, sanitise any objects and surfaces, they may have touched.
Parainfluenza viruses can live on surfaces for up to 10 hours. Use a household cleaner that contains soap or detergent to regularly wash or wipe down surfaces. This can help stop the spread of HPIVs.
Don't share cups, glasses and cutlery with people who are sick with a virus.
There are no vaccines for any of the human parainfluenza viruses.
Resources and support
- Speak with your doctor for more information about HPIVs.
- Ask your pharmacist how to manage your symptoms at home.
- Learn more about colds and flu.
- You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with you 24 hours a day, 7 days a week.
Learn more here about the development and quality assurance of healthdirect content.
Last reviewed: March 2025
