parainfluenza virus

infectious agent

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Last updated

July 17, 2026

Quick Summary

Parainfluenza viruses are a group of viruses that frequently cause lower respiratory tract infections, particularly in infants and children. These infections can manifest as illnesses such as croup.1

Parainfluenza viruses are classified under the genera Respirovirus and Orthorubulavirus. They are among the various viruses responsible for acute respiratory diseases. While often causing milder symptoms, parainfluenza viruses are capable of causing severe illness.12

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croup
Viral croup
…viral infection—most frequently with the parainfluenza and influenza viruses. Such infections are most prevalent among children under age three, and they strike most frequently in late fall and winter. Generally, the onset of viral croup is preceded by symptoms of the common cold for several days.
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…viral infection—most frequently with the parainfluenza and influenza viruses. Such infections are most prevalent among children under age three, and they strike most frequently in late fall and winter. Generally, the onset of viral croup is preceded by symptoms of the common cold for several days.
Read More