Symptoms of Parainfluenza Virus: What to Know

The symptoms of parainfluenza virus in adults are usually those of a common cold: a runny nose, sore throat, cough and sometimes a mild fever. Human parainfluenza viruses, or HPIVs, are a group of respiratory viruses that infect the nose, throat and airways, and most of us catch them many times in a lifetime. Knowing the symptoms of parainfluenza virus helps you care for yourself at home and spot the signs that need a doctor.

Key takeaways

• HPIV is a common respiratory virus that usually causes a cold in adults and croup in young children.
• No antiviral medicine targets HPIV, so care means rest, drinks and simple pain relief.
• Most adults feel better within a week, though tiredness or a tickle in the chest can linger for a few weeks.
• Older adults and people with a weakened immune system are more likely to develop pneumonia.
• Call 000 for severe trouble breathing, blue lips or chest pain.

Parainfluenza: A Common Viral Infection of the Airways

Human parainfluenza is a viral infection of the airways, from the nose down to the windpipe and, less often, the lungs. The symptoms of parainfluenza virus overlap with a cold and the flu, so the table shows how the three usually compare.

It usually settles on its own, but in older adults or people with lung disease it can spread lower and lead to a chest illness such as bronchitis.

How a Doctor Diagnoses Parainfluenza

A doctor usually diagnoses HPIV from the story of your symptoms and how the illness has unfolded, because care at home is the same whichever cold virus is to blame. Parainfluenza symptoms such as a blocked nose, cough and hoarse voice look much like other colds, so a test is only worth doing when the result would change what happens next. That might be in hospital, during an outbreak in aged care, or for someone with weak immunity, when a nose or throat swab can be tested for HPIVs and other respiratory viruses at once.

By phone, a Medio GP cannot listen to your chest, but can ask about the symptoms of parainfluenza virus, how fast they came on and who else is sick, and give a pathology request for a swab where it would change your care. In young children the same viruses can narrow the windpipe, so a GP needs to see the child in person.

How Parainfluenza Infects the Nose, Throat and Windpipe

The virus gets in through the nose or eyes and multiplies in the cells lining the nose, throat and windpipe, which swell and make extra mucus. That swelling explains the symptoms of parainfluenza virus: a blocked nose, a scratchy throat, a hoarse voice and a cough. In a small child's narrow windpipe, the same swelling causes croup, with its seal-like bark and noisy breathing.

In adults the illness usually stays in the upper airways. Sometimes HPIV moves down to cause a lower respiratory infection such as bronchitis or pneumonia, especially in older people and those with heart or lung disease. Symptoms usually start 2 to 7 days after contact with the virus.

The Four Types of Human Parainfluenza Virus

There are four types of human parainfluenza viruses, numbered 1 to 4, and each tends to cause a slightly different illness. What is the parainfluenza virus, in simple terms? It is a common germ from the same family as mumps and measles, but a far milder one.

Types 1 and 2 are the main causes of croup in children. Type 3 is the most common type overall, and the one most likely to cause bronchiolitis or pneumonia, a lower respiratory illness. Type 4 is tested for less often and usually causes mild parainfluenza symptoms, much like a cold.

Catching one type gives only short-lived protection, and the immune system does not fully guard against the other types, so human parainfluenza can come back several times in a lifetime. Human parainfluenza viruses also tend to cause milder illness each time.

Home Care for Symptoms of Parainfluenza Virus

Home care eases the symptoms while your body clears the virus, which usually takes about a week. There is no specific parainfluenza treatment, and antibiotics do not work on viruses. Rest, drink plenty of fluids and take paracetamol or ibuprofen for a sore throat, aches or a temperature, following the packet directions.

Honey in warm water, lozenges, a saline nose spray and a steamy shower can soothe a cough and a blocked nose, and it helps to keep away from cigarette smoke. Parainfluenza vs flu makes a difference here: influenza has antiviral medicines for people at high risk, which are only available on prescription in Australia, but HPIV has none.

Everyday Ways to Avoid Catching Parainfluenza

Washing your hands often with soap and water is the best everyday protection, because HPIV passes mostly through hands, coughs and sneezes. The virus can survive for hours on door handles, phones and keyboards, so clean shared surfaces often, and keep your hands away from your eyes, nose and mouth.

Cover coughs and sneezes with a tissue or your elbow. If you are sick, stay home until your temperature has settled and you feel well, even if a runny or blocked nose hangs on. This matters most around babies, older people and anyone in aged care, where outbreaks spread quickly. There is no vaccine against HPIV, but a yearly flu shot is still worth having, as it guards against an illness with similar early signs.

When Symptoms of Parainfluenza Virus Need a Doctor

See a doctor if your symptoms last more than 10 days, get worse after starting to improve, or come with a high temperature for more than 3 days, as these can mean a lower respiratory infection or a second, bacterial one. Get advice sooner if you are older or pregnant, or live with asthma, lung disease, heart disease or a weakened immune system, because HPIVs are more likely to cause pneumonia in these groups.

Call 000 if you have severe shortness of breath, chest pain, blue lips or confusion, and see a doctor the same day if you are coughing up blood. A child with noisy breathing or a harsh bark should see a GP in person, and you should call 000 if they are struggling to breathe.

A Medio GP can talk through your symptoms in a phone consult and advise on parainfluenza treatment at home. Where the doctor thinks it right, they can give a pathology request for a swab that also checks for flu and other respiratory infections, or send an eScript if they find a bacterial illness that needs antibiotics.

How Common Parainfluenza Is Across the Year

HPIVs are among the commonest causes of respiratory infections, and most children have caught at least one type by the age of five. In Australia they circulate all year, and the types peak at different times, with type 3 often most common in spring.

An infected person can pass the virus on while they have symptoms, usually for about a week and sometimes longer. Adults can be infected again and again because protection fades, though each new bout is usually milder, often no more than a sniffle. Croup in young children tends to rise in autumn, when types 1 and 2 are about.

Summary

The symptoms of parainfluenza virus are usually those of a cold, with a cough, a hoarse voice and a blocked nose that settle within a week or two, while young children can become more unwell. Rest, fluids and simple pain relief are the main care, and there is no vaccine. If the symptoms of parainfluenza virus are dragging on or worrying you, a Medio GP can assess you by phone, advise on care at home and, where the doctor thinks it right, give a pathology request for a swab or send an eScript.

Frequently asked questions

What are human parainfluenza viruses and what are their symptoms?

Human parainfluenza viruses are four common respiratory viruses that infect the nose and chest. Their signs and symptoms in adults are a runny or blocked nose, a scratchy throat, a cough, a hoarse voice and sometimes a mild temperature. In children they can cause croup or bronchiolitis, and a child with noisy breathing should see a GP in person.

What are the common symptoms of a viral illness?

Most viral illnesses bring tiredness, aches and sore muscles, a headache and sometimes a raised temperature, plus symptoms from wherever the virus settles: a blocked nose with a cold, a tight or wheezy chest with a chest virus, or vomiting and diarrhoea with a gut virus. Most settle on their own within one to two weeks, and antibiotics do not help them.

Can a doctor help with symptoms of parainfluenza virus?

A doctor cannot cure the virus, but can help work out whether your illness is a simple cold or something needing other treatment, such as pneumonia, a bacterial infection or flu. A Medio GP can assess you by phone, advise on easing your symptoms at home, and arrange a swab through a pathology request where it would change your care.

How long does it take to recover from parainfluenza?

Most adults feel better within a week, although a tickly chest or tiredness can last two or three weeks after the other symptoms have gone. Recovery tends to take longer in older adults and in people with lung disease. If you are getting worse rather than better after a week, see a doctor.

Can adults get parainfluenza?

Adults catch it often, because protection after each bout fades and there are four types. The virus affects children and adults differently: young children may get croup or a wheezing illness, while most adults get a cold. Older adults and people with weak immunity are more likely to become seriously unwell, so they should see a doctor sooner.

Is parainfluenza worse than flu?

Usually not. Influenza more often causes a high temperature, severe aches and complications, and there is a yearly flu vaccine to lower that risk. The viruses spread in the same way, through coughs, sneezes and hands, and HPIV can still be serious for babies, older adults and people with weak immunity.