Definition:
Parainfluenza viruses are paramyxoviruses, of which there are 4 distinct serotypes. Parainfluenza viruses are the second most common cause of lower respiratory tract infections in young children.
Diagnosis:
The presence of Parainfluenza infections can be confirmed through cell cultures, immunofluorescent microscopy, and PCR. Currently, no vaccines exist to prevent Parainfluenza infections. However, research is underway for HPIV-1, -2, and -3 vaccines.
Treatment:
Parainfluenza treatment is mostly supportive and symptomatic.
Symptoms and Signs:
In general, symptoms of parainfluenza viruses include: fever; nonproductive to minimally productive cough; nasal congestion; inspiratory stridor; pharyngeal erythema; rales; rhonchi; and wheezing. In most cases, the epiglottis is greatly swollen due to viral infection, consequently causing severe airway obstruction. In severe cases, such as in immunocompromised hosts, parainfluenza virus can lead to serious complications such as respiratory failure and death.
Causes:
Parainfluenza illnesses are caused by four serotypes of viruses belonging to the paramyxoviruses family: (1) HPIV-1; (2) HPIV-2; (3) HPIV-3; and (4) HPIV-4. Parainfluenza is commonly acquired via inhalation of contaminated droplet nuclei, or indirectly though contact with infected secretions. The virus has an incubation period of 2-6 days.
