Treatment of Human Metapneumovirus Infection
For immunocompetent patients, provide supportive care only—no antiviral therapy is indicated, as no agent has proven efficacy for hMPV treatment. 1
Immunocompetent Adults and Children
Supportive care remains the sole evidence-based approach for otherwise healthy individuals with hMPV infection. 1
- Rest, hydration, and symptomatic management constitute the mainstays of therapy 1
- Oxygen therapy should be titrated to maintain adequate saturation in patients with respiratory compromise 1
- Monitor vital signs, oxygen saturation, and respiratory status 1
- Maintain fluid and electrolyte balance 1
- Treat bacterial superinfection if suspected or documented with appropriate antibiotics 1
Most hMPV infections are mild to moderate, resolve spontaneously, and require only outpatient management 2. The disease typically presents as upper respiratory tract infection with flu-like symptoms 3.
Immunocompromised Patients and Severe Disease
For immunocompromised patients with hMPV lower respiratory tract disease (LRTD), consider treatment with ribavirin and/or intravenous immunoglobulin, despite the absence of randomized controlled trial data supporting this approach. 1
When to Consider Antiviral Therapy
- Lower respiratory tract involvement (pneumonia, bronchitis, bronchiolitis) in immunocompromised patients warrants consideration of ribavirin and/or IVIG 3, 1
- Hematopoietic stem cell transplant recipients and leukemia patients with pneumonia specifically merit this consideration 1
- Upper respiratory tract infection alone does not typically warrant antiviral therapy, even in immunocompromised patients 1
Important Caveats
The evidence for ribavirin and IVIG is limited to case reports and observational studies—no randomized controlled trials support their efficacy 3, 4. Single cases of severe disease and fatal outcomes have been reported even with treatment attempts 1. hMPV is frequently codetected with other pathogens (bacteria, fungi, other viruses, cytomegalovirus) in pneumonia cases, which obscures the true attributable morbidity and complicates treatment decisions 3, 1.
Risk Factors for Severe Disease
Patients at highest risk for progression to LRTD and severe outcomes include:
- High viral load 5
- Coinfection with other respiratory pathogens, especially respiratory syncytial virus 5
- Age 0-5 months or >65 years 5
- Immunodeficiency states 5
- Hematopoietic stem cell transplant recipients, particularly early post-transplant 3
- Higher corticosteroid exposure 3
- Neutropenia and lymphopenia 3
Infection Control Considerations
Implement standard and droplet precautions to prevent nosocomial transmission, as hMPV demonstrates asymptomatic and prolonged shedding, particularly in HSCT patients. 1
- Asymptomatic shedding rates may be substantial in immunocompromised populations 3, 1
- Prolonged viral shedding has been documented in HSCT patients 3, 1
- Nosocomial outbreaks can occur given the estimated incubation period of 2.6 days and high rates of asymptomatic shedding 3
Current State of Antiviral Development
No hMPV-specific vaccine or antiviral therapy has been approved for clinical use 6. Ribavirin remains the only possible treatment option despite its limitations 2. Various vaccination strategies are being explored and tested in animal models, but further studies are required to define optimal treatment and prevention strategies 5.