Human parainfluenza virus (HPIV) -Paramyxoviridae family- commonly causes 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 cough, runny nose, and fever. HPIVs can cause more severe lower respiratory illness, such as pneumonia or croup. 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.