Parainfluenza
Human parainfluenza virus; HPIVsParainfluenza refers to a group of viruses that lead to upper and lower respiratory infections.
Causes
There are four types of parainfluenza virus. They can all cause lower or upper respiratory infections in adults and children. The virus can cause croup, bronchiolitis, bronchitis and certain types of pneumonia.
Upper respiratory infections
The common cold most often causes a runny nose, nasal congestion, and sneezing. You may also have a sore throat, cough, headache, or other symptoms....
Croup
Croup is an infection of the upper airways that causes breathing difficulty and a barking cough. Croup is due to swelling around the vocal cords. I...
Bronchiolitis
Bronchiolitis is swelling and mucus buildup in the smallest air passages in the lungs (bronchioles). It is usually due to a viral infection....
Bronchitis
Acute bronchitis is swelling and inflamed tissue in the bronchi, the main passages that carry air to the lungs. This swelling narrows the airways, w...
The exact number of parainfluenza cases is unknown. The number is suspected to be very high. Infections are most common in fall and winter. Parainfluenza infections are most severe in infants and become less severe with age. By school age, most children have been exposed to the parainfluenza virus. Most adults have antibodies against parainfluenza, although they can get repeat infections.
Symptoms
Symptoms vary depending on the type of infection. Cold-like symptoms consisting of a runny nose and mild cough are common. Life-threatening respiratory symptoms can be seen in young infants with bronchiolitis and those with weak immune system.
In general, symptoms may include:
- Sore throat
- Fever
- Runny or stuffy nose
- Chest pain, shortness of breath, wheezing
Wheezing
Wheezing is a high-pitched whistling sound during breathing. It occurs when air moves through narrowed breathing tubes in the lungs.
Read Article Now Book Mark Article - Cough or croup
Exams and Tests
A physical exam may show sinus tenderness, swollen glands, and a red throat. The health care provider will listen to the lungs and chest with a stethoscope. Abnormal sounds, such as crackling or wheezing, may be heard.
Tests that may be done include:
-
Arterial blood gases
Arterial blood gases
Blood gases are a measurement of how much oxygen and carbon dioxide are in your blood. They also determine the acidity (pH) of your blood.
Read Article Now Book Mark Article -
Blood cultures (to rule out other causes of pneumonia)
Blood cultures
A blood culture is a laboratory test to check for bacteria or other germs in a blood sample.
Read Article Now Book Mark Article -
Chest x-ray
Chest x-ray
A chest x-ray is an x-ray of the chest, lungs, heart, large arteries, ribs, and diaphragm.
Read Article Now Book Mark Article -
CT scan of the chest
CT scan of the chest
A chest CT (computed tomography) scan is an imaging method that uses x-rays to create cross-sectional pictures of the chest and upper abdomen....
Read Article Now Book Mark Article -
Complete blood count (CBC)
Complete blood count (CBC)
A complete blood count (CBC) test measures the following:The number of white blood cells (WBC count)The number of red blood cells (RBC count)The numb...
Read Article Now Book Mark Article - Swab of nose for rapid viral test including the virus that causes COVID-19
Treatment
There is no specific treatment for the viral infection. Certain treatments are available for the symptoms of croup and bronchiolitis to make breathing easier.
Outlook (Prognosis)
Most infections in adults and older children are mild and recovery takes place without treatment, unless the person is very old or has an abnormal immune system. Medical intervention may be necessary if breathing difficulties develop.
Breathing difficulties
Breathing difficulty may involve:Difficult breathing Uncomfortable breathingFeeling like you are not getting enough air
Possible Complications
Secondary bacterial infections are the most common complication. Airway obstruction in croup and bronchiolitis can be severe and even life threatening, especially in younger children.
Airway obstruction
Breathing difficulty may involve:Difficult breathing Uncomfortable breathingFeeling like you are not getting enough air
When to Contact a Medical Professional
Contact your provider if:
- You or your child develops croup, wheezing, or any other type of breathing difficulty.
- A child under 18 months develops any type of upper respiratory symptom.
Prevention
There are no vaccines available for parainfluenza. A few preventive measures that may help include:
- Avoid crowds to limit exposure during peak outbreaks.
- Wash your hands often.
- Limit exposure to day care centers and nurseries, if possible.
References
Ison MG. Parainfluenza viruses. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 156.
Weinberg GA, Edwards KM. Parainfluenza viral disease. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 339.
Welliver Sr RC. Parainfluenza viruses. In: Cherry JD, Harrison GJ, Kaplan SL, Steinbach WJ, Hotez PJ, eds. Feigin and Cherry's Textbook of Pediatric Infectious Diseases. 8th ed. Philadelphia, PA: Elsevier; 2019:chap 179.
Review Date: 7/31/2022
Reviewed By: Denis Hadjiliadis, MD, MHS, Paul F. Harron Jr. Professor of Medicine, Pulmonary, Allergy, and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
All rights reserved.