The Paramyxoviruses are an important cause of respiratory disease in children. Illnesses include croup, bronchiolitis and pneumonitis.
Paramyxoviruses replicate in the cytoplasm and are released by budding.
Virus-specific antigens include those associated with the envelope and those contained within the nucleocapsid. The host range for the Paramyxoviruses includes humans and monkeys. Parainfluenza viruses are the most common cause of croup and there are 4 serotypes, numbered 1-4. Some severe manifestations can result from infection but there is only one serotype. Another acute childhood disease, measles virus commonly causes a fever with a rash, occasionally producing conjunctivitis and, sometimes, pneumonia.