Human Parainfluenza Viruses
Human parainfluenza viruses, belonging to the paramyxovirus family, are a group of four distinct serotypes of enveloped single-stranded RNA viruses. They are the second most common cause of lower respiratory tract infection in younger children.
Many times the host has repeat infections throughout life with symptoms that may include upper respiratory tract illness or more commonly, a cold and sore throat. It can also cause severe pneumonia in immunosuppressed people. There is currently no vaccine although research is under way. Many times soap and water can inactivate the virus.
The incubation period of all four serotypes is 1 to 7 days. In immunosuppressed people, such as transplant patients, parainfluenza virus infections can cause severe pneumonia, which can be fatal.