Human parainfluenza viruses (HPIVs) are respiratory illnesses that can affect children and older individuals. Young children and adults with compromised immune systems may also be at higher risk of developing one of the four different types of human para influenza viruses.

HPIVs spread through the air and are transmitted through coughing. Close personal contact like shaking hands with someone infected with HPIV is also a key way that the virus is transmitted from one person to another.

Touching objects like door handles or surfaces and then touching your own mouth or nose is another way that you might pick up the parainfleunza virus. Frequently washing your hands is highly recommended.

Symptoms of HPIVs

An HPIV that causes an upper respiratory illness may cause a fever as well as a cough and runny nose. A severe lower respiratory illness caused by HPIVs can result in any of the following symptoms: bronchitis, bronchiolitis, pneumonia, or croup.

  • Croup (Upper Airway Infection)

Croup is an infection of the upper airway that blocks breathing and may have a distinctive barking cough that physicians are skilled at spotting. Croup is especially common in young infants and can cause a baby’s upper airways to swell to the point that breathing becomes difficult.

A raspy voice and a cough that sounds like a higher pitched dog bark are signs that an HPIV may have caused croup. The parainfluenza virus is the most common cause of croup, although croup itself may be viral or spasmodic in origin. Croup caused by an HPIV may start out as a cold before turning into a harsh sound indicative of upper respiratory distress – known as “stridor” to medical professionals.

  • Bronchitis and Bronchiolitis

Bronchitis is an infection of the main air passages going from your windpipe to your lungs whereas bronchiolitis is inflammation (“itis” meaning inflammation in medical parlance) and infection in the smaller air passages in your lungs. Both of these conditions can be caused by human parainfluenza viruses.

Bronchitis is technically inflammation of the lining of the bronchial tubes. Your bronchial tubes carry air to your lungs as well as take air away from your lungs. Colds and respiratory infections can cause acute bronchitis, and that’s often the kind of bronchitis that an HPIV will cause in a patient who’s been exposed to one of the four kinds of HPIV. Chronic bronchitis is a more serious condition requiring medical treatment.

  • Other HPIV Symptoms to Look For

A sore throat or constant wheezing might also be symptoms that manifest after being exposed to a human parainfluenza virus. Ear pain and decreased appetite are two lesser known, though still characteristic, symptoms that can accompany HPIV. So, if your child or an older adult displays a cough, fever, a raspy voice, and a sore throat, then it may be time to look into whether or not that individual has an HPIV-related infection.

Among the four main types of HPIV, HPIV-1 and HPIV-2 have been strongly associated with croup is babies and younger children. Both of these types of human parainfluenza virus can cause symptoms that resemble the flu or common cold in babies, children, and adults of all ages. It’s the HPIV-3 that can present more worrisome symptoms in older adults.

HPIV-3 has been more strongly associated with bronchitis, bronchiolitis, and pneumonia among older adults. Although some respiratory distress has been associated with HPIV-4, the severity of symptoms with HPIV-4 is usually somewhat lower than HPIV-3. If you or a loved one has severe symptoms that don’t seem to improve on their own over about a week, then seek the care of a trained medical professional immediately.