What are human parainfluenza viruses?
Human parainfluenza viruses (HPIV) are a group of viruses that cause different types of respiratory infections and are most common in children and babies. Most HPIV usually cause infections of the upper airway such as a common cold, ear infections, or sore throat. Other infections caused by HPIV include infections of the lower respiratory tract such as croup (an infection of the airway below the larynx, or “voice box,” that is characterized by a barky cough and harsh, noisy breathing), pneumonia, or bronchiolitis (an inflammation of the lower airways). • Croup outbreaks usually occur during the fall season and alternate every other year. • Lower respiratory tract infections occur during the spring and summer and often continue into the fall. • Children between the ages of 2 and 6 are most likely to develop croup. • Children under the age of 2 are more likely to develop lower respiratory tract infections such as pneumonia or bronchiolitis. • Reinfections can occur after the first infect
