Laboratory Diagnosis

Infection with human parainfluenza viruses (HPIVs) can be confirmed by—

• direct detection of viral genome by polymerase chain reaction (PCR) assay,
• direct detection of viral antigens in respiratory secretions (collected within 1 week of symptom onset) using immunofluorescence or enzyme immunoassay,
• isolation and identification of the virus in cell culture, or
• demonstration of a significant rise in HPIV-specific IgG antibodies between appropriately collected paired serum specimens or specific IgM antibodies in a single serum specimen.