Parainfluenza viruses causes lower respiratory tract infections in children. Parainfluenza viruses are membrane-bound single-stranded RNA viruses and part of the family Paramyxoviridae. Four serotypes, designated 1, 2, 3 and 4 are recognized. Types 1 and 2 generally induce laryngotracheobronchitis but occasionally cause pneumonitis.||Storage and Stability:|Aliquot to avoid repeated freezing and thawing and store at -70°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.