What is the management and treatment of human metapneumovirus (HMPV) infection?

Management and Treatment of Human Metapneumovirus (HMPV) Infection

Treatment for human metapneumovirus (HMPV) infection is primarily supportive care, as there are currently no specific antiviral therapies or vaccines approved for HMPV. 1

Clinical Presentation and Diagnosis

• HMPV causes respiratory tract infections ranging from mild cold-like symptoms to severe pneumonia and acute respiratory distress syndrome (ARDS)
• Common symptoms include:
  • Fever (most common)
  • Cough
  • Breathlessness
  • Fatigue
• Diagnosis is typically made via PCR-based viral panels on respiratory specimens 1
• Low-dose chest CT is indicated in patients with symptoms consistent with lower respiratory tract disease 2

Management Approach

General Supportive Care

1. Oxygen therapy: Provide supplemental oxygen for hypoxemic patients
2. Hydration: Ensure adequate fluid balance
3. Antipyretics: For fever management
4. Rest: Encourage adequate rest during recovery period

Severe Disease Management

For patients with severe HMPV infection leading to ARDS:

1. Mechanical ventilation: Use low tidal-volume strategy for ARDS 2
2. Conservative fluid management: For ARDS patients without tissue hypoperfusion 2
3. Extracorporeal membrane oxygenation (ECMO): Consider in cases of severe refractory hypoxemia when standard therapy is failing 2, 3
   • VV-ECMO may be used in severe cases with lung injury score > 3 or pH < 7.2 due to uncompensated hypercapnia
   • Should only be performed at centers with appropriate expertise

Special Populations

Immunocompromised patients:

• At higher risk for severe disease and prolonged viral shedding 1
• Case reports suggest potential benefit from:
  • Ribavirin (aerosolized and oral)
  • Intravenous immunoglobulin (IVIG)
  • Consider in severe disease, though efficacy remains unclear 4, 5

Infection Control Measures

• Hand hygiene with alcohol-based hand gels
• Respiratory/cough etiquette
• Isolation of infected individuals, especially in healthcare settings
• Extended isolation precautions for immunocompromised patients due to potential for prolonged viral shedding 1

Antimicrobial Considerations

• Empiric antibiotics should be considered only if bacterial superinfection is suspected
• Avoid blind or improper combination of broad-spectrum antibiotics 2
• If influenza co-infection is suspected and within 48 hours of symptom onset, consider oseltamivir or baloxavir 2

Prevention

• No specific vaccine is currently available for HMPV 1, 6
• Preventive measures focus on infection control:
  • Hand hygiene
  • Respiratory etiquette
  • Physical distancing during outbreaks
  • Avoiding close contact with infected individuals

Monitoring and Follow-up

• Monitor respiratory status and oxygen saturation
• For patients with underlying conditions (especially immunocompromised), closer follow-up may be needed due to risk of prolonged illness and complications
• Consider repeat testing in immunocompromised patients to document viral clearance before discontinuing isolation 1

Common Pitfalls

1. Failing to consider HMPV in adults with respiratory symptoms (not just a pediatric disease)
2. Overuse of antibiotics when viral etiology is confirmed
3. Inadequate isolation precautions, particularly for immunocompromised patients
4. Underestimating the potential severity in high-risk populations (elderly, immunocompromised)

HMPV should be included in the differential diagnosis for patients with acute respiratory illness, especially during winter and spring seasons when the virus is most prevalent 7.