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Doctor listening to girls lungs with stethoscopeHuman parainfluenza viruses (HPIVs) commonly cause upper and lower respiratory illnesses in infants and young children. But, anyone can get respiratory illness from HPIV.

Symptoms of upper respiratory illness may include fever, runny nose, and cough. HPIVs can cause more severe lower respiratory illness, such as croup or pneumonia. Young children are more likely to have these severe illnesses. But, older adults and people with weakened immune systems are also at risk.

You can have multiple HPIV illnesses in your lifetime.

HPIVs spread from person to person through close personal contact, in the air by coughing and sneezing, and by touching objects or surfaces that have HPIVs on them.

People usually get infected with HPIV in the spring, summer, and fall.

Different Types of HPIVs

  • HPIV-1 and HPIV-2 may cause cold-like symptoms in people who are infected. HPIV-1 often causes croup in children; HPIV-2 can also cause croup.
  • HPIV-3 is more often associated with bronchiolitis, bronchitis, and pneumonia.
  • HPIV-4 is not recognized as often, but may cause mild to severe respiratory tract illnesses.
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