Infectious Diseases

Human Parainfluenza Viruses (HPIV)

What are human parainfluenza viruses?

Human parainfluenza viruses (HPIV) are a group of viruses that cause different types of respiratory infections and are most common in children and babies. Most HPIV usually cause infections of the upper airway such as a common cold, ear infections, or sore throat. Other infections caused by HPIV 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 alternate every other year.
  
  
• Lower respiratory tract infections occur during the spring and summer and often continue into the fall.
  
  
• Children between the ages of 6 months and 3 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 HPIV transmitted?

HPIV can occur by either direct contact with respiratory secretions from an infected person or by coming in contact with infectious material then touching your eyes, nose, or mouth. Most children develop an infection with HPIV before they are 5 years old.

What are the symptoms of HPIV?

The following are the most common symptoms of HPIV infections. However, each child may experience symptoms differently. Symptoms may include:

• runny nose
• redness or swelling of the eyes
• barky cough
• noisy, harsh breathing
• hoarse voice or cry
• rattling felt over the chest or back
• wheezing
• fever
• irritability
• decreased appetite
• vomiting
• diarrhea

How are HPIV 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:

• blood work
  
  
• nasal swab of respiratory secretions
  
  
• chest x-ray - a diagnostic test which uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film.

Treatment for HPIV:

Once a child is infected, treatment is supportive (aimed at alleviating the symptoms present). Because a virus causes the infection, antibiotics are not useful. Specific treatment will be determined by your child's physician based on:

• your child's age, overall health, and medical history
• extent of the disease
• your child's tolerance for specific medications, procedures, or therapies
• expectations for the course of the disease
• your opinion or preference

HPIV usually cause mild symptoms of a common cold, but are also a common cause of croup. Croup symptoms can be very scary for parents. Supportive treatment for croup may include:

• Take your child into cool, night air. A bathroom with the shower running may also help ease your child's breathing.
  
  
• Encourage your child to drink plenty of fluids.
  
  
• Treat a fever with acetaminophen or ibuprofen (as instructed by your child's physician)
  
  
• Keep your child as quiet and calm as possible to help decrease the breathing effort.

Prevention of HPIV:

Strict hand washing is important to prevent the spread of HPIV to other infants and children. If your child is in the hospital, healthcare 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 for HPIV, but, currently, there is no immunization for the virus.