Metapneumovirus - hMPV

The human metapneumovirus (hMPV) is a recently discovered (2001) agent of viral respiratory infections.

Epidemiology

• Prevalence – accounts for 5-10% of respiratory infections in hospitalized children and 10-20% of infections in outpatient clinics
• Age – most common in children <10 years of age
  • By the age of 5, nearly all children show evidence of past infection
  • Transmission – aerosol
• Peak season is November through May

Organism

• Single-stranded RNA virus
• Member of the Paramyxoviridae family
• Two strains that occur concurrently – A and B

Risk Factors

• Children
• Elderly
• Immunocompromised persons

Clinical Presentation

• Clinical symptoms indistinguishable from respiratory syncytial virus (RSV)
• Symptoms range from common cold to severe lower respiratory tract infections (bronchitis, pneumonia)
• May exacerbate asthma as well as play an etiology role in its development
• Co-infections with RSV and adenovirus are common

Treatment

• Supportive

Diagnosis

• Laboratory testing
  • Direct fluorescent antibody (DFA) – most useful test, rapid
  • Polymerase chain reaction (PCR) – most sensitive test
  • Culture – organism is difficult to grow and poorly recovered

Differential Diagnosis

• Influenza
• Parainfluenza
• Respiratory Syncytial  Virus
• Mycoplasma pneumonia
• Legionella
• Chlamydophila pneumonia

Indications for Ordering

• Tests generally appear in the order most useful for common clinical situations
• Click on number for test-specific information in the ARUP Laboratory Test Directory