Human Metapneumovirus (HMPV) is a viral respiratory infection that affects people of all ages. Here are the key points about HMPV:
Transmission:
- Spread through secretions from coughing and sneezing
- Close personal contact, such as touching or shaking hands
- Touching objects with viruses on them and then touching the mouth, nose, or eyes
Symptoms and Severity:
- Typically causes mild to moderate respiratory symptoms, such as cough, fever, and runny nose
- Can cause more severe illness in certain individuals, such as older adults, young children, and people with underlying health conditions
- No conclusive evidence that any one strain is dominant or causes varying levels of severity
Epidemiology:
- Peak infection in the northern hemisphere occurs in late winter and early spring
- Found globally across all continents, with a complex and dynamic distribution
- Can differ significantly from community to community, allowing for the possibility of different strains circulating in different locations
Genotypes:
- At least two major genotypes (A and B), each with two sub-genotypes
- No one strain is dominant over the others
Treatment and Prevention:
- No reliable antiviral therapy treatment or vaccine available as of 2023
- Development of vaccines and antiviral therapies is ongoing, with promising results in animal models
- Ribavirin has shown effectiveness in an animal model
- Moderna conducted a clinical trial for a candidate mRNA vaccine against metapneumovirus, which has passed phase I and shown to be well-tolerated and provoke an immune response
Outbreaks:
- Hospital-acquired infections with HMPV have been reported
- Circulates during fall and winter months with alternating predominance of a single subtype each year
- Recent outbreaks reported in China, Malaysia, Hong Kong, Kazakhstan, and India
History:
- First reported in 2001
- Avian metapneumovirus was first reported in the 1970s
- Bayesian estimates suggest that human metapneumovirus emerged 119-133 years ago and diverged from avian metapneumovirus around 1800.