From the Guidelines
Human metapneumovirus (hMPV) is a paramyxovirus that causes upper respiratory tract infections (URTI) and tracheobronchitis in 5%–20% of children and adults during winter. The virus is a single-stranded RNA virus that can lead to severe lower respiratory tract disease, particularly in vulnerable populations such as immunocompromised individuals, children under five years, and elderly adults 1. Common clinical manifestations of hMPV infection include:
- Cough
- Fever
- Nasal congestion
- Wheezing
- Bronchiolitis
- Pneumonia
hMPV infections are often diagnosed by nucleic acid testing (NAT) and can be asymptomatic or present with flu-like symptoms in hematopoietic stem cell transplant (HSCT) patients 1. The virus can also be codetected with other pathogens, including bacteria, fungi, and other community-acquired respiratory viruses (CARVs), which can obscure the attributable morbidity 1. Treatment of hMPV infection is primarily supportive, and no general recommendation for antiviral treatment can currently be made, although some centers consider treating hMPV lower respiratory tract infections with ribavirin and/or intravenous immunoglobulin (IVIG) despite the lack of supporting studies 1. Prevention measures include good hand hygiene and respiratory etiquette to reduce the transmission of the virus through respiratory droplets and close contact with infected individuals.
From the Research
Human Metapneumovirus (hMPV) RNA
- hMPV is a negative-sense, single-stranded RNA enveloped virus that belongs to the Pneumoviridae family and Metapneumovirus genus 2
- The virus has a genome of approximately 13.3 kb encapsidated by multiple copies of the nucleoprotein (N), giving rise to helical nucleocapsids 3
Clinical Condition Caused by hMPV
- hMPV is associated with respiratory tract infections, which can range from mild and self-limited to severe pneumonia and acute respiratory distress syndrome (ARDS) 4, 5
- The virus can cause bronchiolitis, wheezing, and coughing, and is a significant global pathogen that affects infants, young children, the elderly, and immunocompromised individuals 2, 6
- hMPV infection can lead to acute hypoxemic respiratory failure, and the treatment is supportive as no current antivirals or vaccines are effective or recommended 4, 5
Mechanisms of hMPV Infection
- hMPV induces the formation of inclusion bodies for efficient genome replication and transcription 3
- The virus interferes with several pattern recognition receptors (PRRs) and cell signaling pathways triggered by interferon-associated genes, and promotes an anergic state in T cells 2
- Viral glycoproteins, such as G and SH, may play immune-modulator roles during infection 2