What is Parainfluenza (Human parainfluenza virus)?

From the Guidelines

Parainfluenza viruses should be managed with supportive care, including rest, hydration, and fever control, as antibiotics are ineffective against this viral infection. The management of parainfluenza infections involves a range of strategies to reduce morbidity, mortality, and improve quality of life.

Key Considerations

• Treatment is primarily supportive, focusing on alleviating symptoms such as fever and cough, and ensuring adequate hydration and rest.
• For specific conditions like croup, a single dose of oral dexamethasone (0.6 mg/kg) may be prescribed to reduce airway inflammation, as indicated by general medical knowledge.
• In severe cases requiring hospitalization, supplemental oxygen and occasionally nebulized epinephrine may be necessary, highlighting the importance of monitoring and timely intervention.
• Prevention is crucial and involves good hand hygiene, avoiding close contact with infected individuals, and disinfecting frequently touched surfaces, as emphasized in guidelines for preventing healthcare-associated infections 1.

Infection Control

• Patients with diagnosed or suspected parainfluenza virus infection should be placed in a private room when possible or in a room with other patients with the same infection and no other infection, to minimize the risk of transmission to other patients and contamination of environmental surfaces or equipment 1.
• Limiting the movement or transport of patients from their rooms to essential purposes only can also help in reducing the spread of the virus 1.
• Rapid diagnostic laboratory tests should be performed promptly on patients admitted with symptoms of parainfluenza or adenovirus infection to facilitate early downgrading of infection-control precautions and initiation of treatment when indicated 1.

Community and Healthcare Setting Considerations

• During periods of increased prevalence of symptoms of viral respiratory illness in the community or healthcare facility, and during the RSV and influenza season, attempting prompt diagnosis of respiratory infections caused by RSV, influenza, parainfluenza, or other respiratory viruses is recommended, especially in high-risk patients such as pediatric patients, and those with compromised cardiac, pulmonary, or immune function 1.
• The use of rapid diagnostic techniques can aid in the early identification and management of parainfluenza infections, potentially reducing the severity of illness and the risk of complications.

From the Research

Parainfluenza Virus Overview

• Parainfluenza viruses (PIV) are common respiratory viruses that belong to the Paramyxoviridae family 2.
• There are four serotypes of human parainfluenza viruses (HPIVs) that cause respiratory illnesses in children and adults 3.
• HPIVs bind and replicate in the ciliated epithelial cells of the upper and lower respiratory tract, and the extent of the infection correlates with the location involved 3.

Clinical Manifestations

• Parainfluenza viruses are associated with a wide spectrum of illnesses, including otitis media, pharyngitis, conjunctivitis, croup, tracheobronchitis, and pneumonia 3.
• Uncommon respiratory manifestations include apnea, bradycardia, parotitis, and respiratory distress syndrome, and rarely disseminated infection 3.
• Severe disease and fatal pneumonia may occur in elderly and immunocompromised adults 3.

Diagnosis and Treatment

• Though sensitive molecular diagnostics are available to rapidly diagnose HPIV infection, effective antiviral therapies are not available 3.
• Treatment for HPIV infection is supportive, with the exception of croup, where the use of corticosteroids has been found to be beneficial 3.
• Several novel drugs, including DAS181, appear promising in efforts to treat severe disease in immunocompromised patients, and vaccines to decrease the burden of disease in young children are in development 3.
• Aerosolized or systemic ribavirin in combination with intravenous gamma globulin has been reported in small, uncontrolled series and case reports of immunocompromised patients 2.

Virus Entry and Infection

• Parainfluenza viruses enter cells by fusing directly at the cell surface membrane 4.
• The receptor binding protein of parainfluenza forms a complex with the fusion protein of the virus, remaining stably associated until a receptor is reached 4.
• Understanding the steps in entry leads to several possible strategies to prevent fusion and inhibit infection 4.