How do you treat human metapneumovirus (HMPV)?

Treatment of Human Metapneumovirus (HMPV)

There is no established antiviral therapy for HMPV infection in immunocompetent adults, and treatment remains primarily supportive care. 1

Immunocompetent Patients

For otherwise healthy individuals with HMPV infection:

• Supportive care only is recommended, as no antiviral agent has established efficacy for HMPV treatment 1
• Rest, hydration, and symptomatic management (antipyretics, cough suppressants) are the mainstays of therapy 1
• Monitor for signs of respiratory deterioration, particularly in very young children (<5 months) or adults >65 years who are at higher risk for severe disease 2

Immunocompromised Patients and Severe Disease

The approach differs significantly in high-risk populations, particularly hematopoietic stem cell transplant (HSCT) recipients and patients with hematologic malignancies:

When to Consider Antiviral Treatment

Some centers consider treating HMPV lower respiratory tract disease (LRTID) with ribavirin and/or intravenous immunoglobulin (IVIG) in immunocompromised patients, despite the lack of randomized controlled trial data supporting this approach. 1

• This consideration applies specifically to HSCT recipients and leukemia patients with pneumonia or lower respiratory tract involvement 1
• Upper respiratory tract infection alone in immunocompromised patients does not typically warrant antiviral therapy 1

Treatment Regimens Used in Practice

When treatment is pursued in severe cases:

• Ribavirin (aerosolized and/or oral formulations) combined with IVIG has been reported in case series of immunocompromised patients 3, 4
• Two HSCT patients with severe hMPV pneumonia were successfully treated with this combination in one case series 3
• The efficacy of these treatments has not been established in randomized trials and remains unclear 2, 4

Important Caveats

• HMPV is frequently codetected with other pathogens (bacteria, fungi, other respiratory viruses, CMV) in pneumonia cases, which obscures the true attributable morbidity and makes treatment decisions more complex 1
• Single cases of severe disease and fatal outcomes have been reported even with treatment attempts 1
• No general recommendation for treatment can currently be made based on available evidence 1

Supportive Care Measures

Regardless of immune status, appropriate supportive interventions include:

• Oxygen therapy titrated to maintain adequate saturation (nasal cannula, mask, high-flow nasal oxygen, or mechanical ventilation as needed) 1
• Monitoring of vital signs, oxygen saturation, and respiratory status 1
• Fluid and electrolyte management 1
• Treatment of bacterial superinfection if suspected or documented 1

Infection Control

• HMPV demonstrates asymptomatic and prolonged shedding, particularly in HSCT patients 1
• Standard and droplet precautions should be implemented to prevent nosocomial transmission 1

Future Directions

Multiple vaccine platforms and monoclonal antibodies targeting the HMPV fusion protein are in development, but none are currently approved for clinical use 5. Novel antiviral agents including fusion inhibitors are being investigated but remain experimental 5.