Human Parainfluenza Viruses (HPIVs)
What are human parainfluenza viruses?
Human parainfluenza viruses (HPIVs) are a group of viruses that cause different types
of respiratory infections and are most common in children and babies. Most HPIVs usually
cause infections of the upper airway, such as a common cold, ear infections, or sore
throat. Other infections caused by HPIVs include infections of the lower respiratory
tract, such as croup (an infection of the airway below the larynx, or "voice box,"
that is characterized by a barky cough and harsh, noisy breathing), pneumonia, or
bronchiolitis (an inflammation of the lower airways):
Croup outbreaks usually occur during the fall season and tend to be worse every other
Lower respiratory tract infections occur during the spring and summer and often continue
into the fall.
Children between the ages of 3 months and 5 years are most likely to develop croup.
Children under the age of 2 are more likely to develop lower respiratory tract infections,
such as pneumonia or bronchiolitis.
Reinfections can occur after the first infection, but are usually less severe.
How are HPIVs transmitted?
HPIVs can be spread by either direct contact with respiratory secretions from an infected
person or by coming in contact with infectious material and then touching your eyes,
nose, or mouth. Most children develop an infection with HPIV before they are 5 years
What are the symptoms of HPIVs?
The following are the most common symptoms of HPIV infections. However, each child
may experience symptoms differently or from one type of infection to another. Symptoms
Redness or swelling of the eyes
Barky (seal-like) cough
Noisy, harsh breathing
Hoarse voice when speaking or crying
Rattling felt over the chest or back when breathing
How are HPIVs diagnosed?
In addition to a complete medical history, physical examination of your child, and
knowledge of regional outbreaks, other diagnostic procedures for HPIV may include:
Nasal swab of respiratory secretions
Chest X-ray (a diagnostic test that produces images of internal tissues, bones, and
What is the treatment for HPIVs?
Once a child is infected, treatment is supportive aimed at making your child more
comfortable. Because a virus causes the infection, antibiotics are not useful. Specific
treatment will be determined by your child's health care provider based on:
Your child's age, overall health, and medical history
Extent of the disease with an emphasis on assessing breathing difficulty
Your child's tolerance for specific medications, procedures, or therapies
Expectations for the course of the disease
Your opinion or preference
HPIVs usually cause mild symptoms of a common cold, but are also a common cause of
croup. Croup symptoms can be very scary for parents. Specific treatment will be determined
by your child's health care provider. Supportive treatment for croup may include:
Taking your child into cool, night air. A steamy bathroom with the shower running
may also help to ease your child's breathing.
Encouraging your child to drink plenty of fluids.
Treating a fever with acetaminophen or ibuprofen (as instructed by your child's doctor).
Keeping your child as quiet and calm as possible to help decrease the breathing effort.
How can HPIVs be prevented?
Strict hand-washing is important to prevent the spread of HPIV to other infants and
children. If your child is in the hospital, health care workers may wear special isolation
apparel, such as masks, gowns, and gloves when they enter your child's room. Efforts
are underway to develop a vaccine, but currently there are no immunizations for the