Parainfluenza virus type 3

Parainfluenza  type 3 is one of a group of common viruses known as human parainfluenza viruses (HPIV) that cause a variety of respiratory illnesses.

Parainfluenza virus

Symptoms

Symptoms usually develop between 2 and 7 days from the time of exposure and typically resolve in 7-10 days. Symptoms may include fever, runny nose, and cough. HPIV-3 can also cause bronchiolitis, bronchitis, and pneumonia.

Risk factors

Infants and young children are particularly susceptible to HPIV-3 infections, though older adults and those with a weakened  are also at risk for complications.

Transmission

HPIVs are usually spread from an infected person to others through coughing, sneezing, and/or touching.

Vaccine

There is currently no vaccine to protect against parainfluenza virus infections.

Clinical course

Most HPIV infections resolve on their own and do not require special treatment, though medical intervention may be necessary for severe breathing problems.

Repeat infections

Most adults have antibodies against parainfluenza but can get repeat infections.

Phylogenetic tree based on the N protein sequences of selected paramyxoviruses

Diagnosis

Infection with human parainfluenza viruses (HPIVs) can be confirmed by direct detection of viral genome by polymerase chain reaction (PCR) assay direct detection of viral antigens in respiratory secretions (collected within 1 week of symptom onset) using immunofluorescence or enzyme immunoassay isolation and identification of the virus in cell culture demonstration of a significant rise in HPIV-specific IgG antibodies between appropriately collected paired serum specimens or specific IgM antibodies in a single serum specimen

Prevention and Treatment

Currently, there is no vaccine to prevent HPIV infection. However, researchers are trying to develop vaccines. Also, there is no specific antiviral treatment for HPIV illness. Most HPIV illnesses are mild and typically require only treatment of symptoms.