Understanding the Rise of Human Metapneumovirus in Australia
February 2, 2025
The International Rise
Human metapneumovirus (hMPV) is an increasingly recognised contributor to respiratory illnesses worldwide, including in Australia, in recent months. First identified in 2001 in the Netherlands amongst a group of children, hMPV belongs to the same viral family as respiratory syncytial virus (RSV) and has been found to cause similar illnesses. Although it has been circulating for decades, awareness of its clinical significance has grown due to improved diagnostic techniques and heightened global surveillance of respiratory infections. As Australia approaches its winter season, health professionals should be aware of the virus’s characteristics, its clinical presentations, as we see the rise of hMPV across the Northern Hemisphere over December-January.
hMPV is primarily a respiratory virus that affects individuals of all age groups but poses the greatest risks to infants, older adults, and people with compromised immune systems. The symptoms of hMPV infections overlap significantly with those caused by other respiratory pathogens, such as influenza and RSV, making diagnosis without specific laboratory testing challenging. Typically, individuals infected with hMPV experience mild symptoms, including fever, cough, nasal congestion, and sore throat. These symptoms closely resemble those of a common cold and may go unnoticed or be attributed to other viral infections. However, in vulnerable populations, the virus can cause severe lower respiratory tract illnesses, such as bronchitis or pneumonia, leading to hospitalization.
Vulnerable Populations
The spread of hMPV in Australia reflects global trends observed in the Northern Hemisphere, where increased respiratory infections have been reported during winter. According to the World Health Organization (WHO), hMPV is one of several respiratory viruses, including influenza and RSV, contributing to the seasonal surge in acute respiratory illnesses this year. Surveillance data from the Northern Hemisphere indicate that hMPV detections have been within expected ranges, with no unusual outbreak patterns. However, the presence of hMPV alongside other respiratory viruses creates challenges for healthcare systems, which must manage overlapping epidemics of similar illnesses.
In Australia, hMPV is likely to follow its usual seasonal patterns, with cases peaking in the colder months. The virus spreads through respiratory droplets, making person-to-person contact, crowded environments, and indoor gatherings during winter key drivers of transmission. The co-circulation of hMPV with other respiratory pathogens compounds its impact, as individuals may contract multiple infections simultaneously or sequentially. This co-circulation is particularly concerning for high-risk groups, such as young children and older adults, who may require hospitalisation if they develop complications.
The emergence of hMPV as a significant contributor to respiratory illness has been influenced by multiple factors. One key factor is the interruption of normal viral circulation patterns during the COVID-19 pandemic. With widespread social distancing, mask-wearing, and lockdown measures, many respiratory viruses experienced reduced transmission. As these restrictions eased, a rebound effect was observed, with respiratory viruses returning to pre-pandemic levels or even higher in some regions. This phenomenon has raised concerns that populations may have increased susceptibility to respiratory viruses, including hMPV, due to a lack of recent exposure.
Early Intervention and Recovery
Most individuals infected with the virus recover with supportive care, but severe cases require more intensive interventions, including oxygen therapy or hospitalisation. Diagnostic testing plays a crucial role in distinguishing hMPV from other respiratory pathogens, particularly during winter, when multiple viruses circulate simultaneously. Polymerase chain reaction (PCR) tests, which can identify hMPV with high accuracy, are valuable tools for clinicians seeking to confirm diagnoses and guide treatment decisions.
Public health surveillance is another essential component of managing hMPV. Routine monitoring of respiratory illnesses provides valuable insights into the virus’s prevalence, geographic spread, and impact on healthcare systems. In Australia, expanding surveillance networks to include hMPV could improve our understanding of its epidemiology and help inform public health responses. Additionally, increasing the availability of hMPV-specific diagnostic tests in primary care settings would enable earlier detection and management of cases, potentially reducing the burden on hospitals.
The Winter Ahead
Looking ahead to the coming winter, there are several predictions for hMPV activity in Australia. Based on global trends, the virus is expected to circulate widely, contributing to the overall burden of respiratory illnesses. High transmission rates are likely in regions with colder climates, where indoor gatherings become more common during winter. Vulnerable populations, including young children, older adults, and individuals with underlying health conditions, are expected to experience the most severe outcomes. Health professionals should anticipate an increase in hospitalisations for respiratory illnesses, including those caused by hMPV, and ensure that adequate resources are available to manage this demand.
Effective public health messaging will be crucial in mitigating the impact of hMPV during the winter months. Educating the public about simple preventive measures, such as hand hygiene, mask-wearing in crowded indoor settings, and staying home when unwell, can help reduce the spread of respiratory infections. Vaccination campaigns targeting co-circulating viruses like influenza should also be emphasized, as these efforts can reduce the overall burden on healthcare systems and prevent severe complications.
Next Steps
While hMPV does not currently have a specific antiviral treatment or vaccine, ongoing research may yield new options for prevention and management. In the meantime, supportive care remains the mainstay of treatment, with a focus on symptom relief and management of complications. Health professionals can play a key role in advocating for continued research into hMPV and other respiratory viruses, as well as promoting policies that support public health initiatives.
hMPV is an important respiratory virus that deserves attention as Australia approaches its winter season. Early recognition, accurate diagnosis, and effective public health measures will be critical in reducing the burden of hMPV and ensuring that healthcare systems remain resilient in the face of respiratory illness surges. With proactive planning and collaboration, the healthcare community can mitigate the effects of hMPV and improve outcomes for patients across Australia.
Uddin S, Thomas M. Human Metapneumovirus. [Updated 2023 Jul 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK560910/
The emergence, impact, and evolution of human metapneumovirus variants from 2014 to 2021 in Spain Piñana, Maria et al. Journal of Infection, Volume 87, Issue 2, 103 – 110
