Human Metapneumovirus (HMPV) is increasingly gaining attention, especially in the wake of recent outbreaks in various parts of the world. While it is not a new virus, its similarities to other respiratory illnesses and the winter season’s heightened transmission rates have led to increased monitoring and analysis. This PPHM article delves into what HMPV is, the symptoms it causes, how it compares to other viral infections like Covid-19, and what measures can be taken to prevent its spread.

What is Human Metapneumovirus (HMPV)?

First recognized by researchers in the Netherlands in 2001, Human Metapneumovirus (HMPV) is part of the Pneumoviridae family. Despite being officially identified at the start of the 21st century, studies suggest that HMPV has been circulating among human populations for at least 50 years. This respiratory virus primarily affects the upper respiratory tract, causing symptoms akin to those of the common cold, seasonal flu, or Covid-19.

Recent Focus on HMPV

The recent surge of HMPV cases in China has captured international focus, bringing back memories of the initial stages of the Covid-19 pandemic. This is not due to new virus mutations or developments, but rather the seasonal nature of such infections. Health authorities in China, alongside other nations like India and Malaysia, are actively monitoring the situation. However, reports from China’s Centers for Disease Control and Prevention indicate that while there has been a small increase in HMPV cases, influenza remains more prevalent, with no overwhelming burden on the healthcare system.

HMPV vs. Covid-19

Though both HMPV and Covid-19 are respiratory viruses, they originate from different families. HMPV is from the Pneumoviridae family, whereas the virus behind Covid-19, SARS-CoV-2, belongs to the Coronaviridae family. Despite these differences, they share common methods of transmission—primarily through respiratory droplets—and produce similar symptoms such as cough, fever, nasal congestion, and shortness of breath. However, the health impact and spread of Covid-19 were significantly more severe, as Covid-19 was a novel virus with no pre-existing immunity in humans.

Symptoms and Treatment of HMPV

HMPV generally leads to mild upper respiratory tract infections, with symptoms often indistinguishable from the flu. These include cough, fever, and nasal congestion. While most individuals experience mild symptoms, the very young, particularly children under two, and individuals with weakened immune systems, such as the elderly and those with advanced cancer, are at higher risk of experiencing severe symptoms. These can escalate to wheezing, breathlessness, and croup-like symptoms, occasionally necessitating hospital care. A “small but significant proportion” of immunocompromised individuals might develop severe conditions affecting the lungs.

Currently, there is no specific vaccine or antiviral treatment for HMPV. Healthcare providers focus on​ symptomatic relief, advising rest, increased fluid intake, and medications to alleviate pain and fever. Severe cases may require more intensive medical intervention.

Prevention of HMPV Infection

Preventive measures for HMPV are similar to those recommended for other respiratory illnesses. These include:

• Practicing good hygiene by washing hands frequently with soap and water.
• Minimizing contact with individuals who are infected or showing symptoms of respiratory illnesses.
• Wearing masks in crowded or enclosed spaces, especially for those at a higher risk of severe illness.
• Keeping a safe distance from others if you are at risk or feeling unwell.

Additionally, individuals are advised to consider vaccinations against other respiratory viruses, such as the flu and respiratory syncytial virus (RSV), particularly for vulnerable groups like pregnant women and older adults.

HMPV in Malaysia and the UK

Malaysia has documented cases of HMPV, with an increase in reported cases from 225 in 2023 to 327 in 2024. The Malaysian Health Ministry emphasizes that while HMPV is not a new pathogen, it does not require mandatory reporting under current health regulations. The public is advised to maintain vigilance and seek medical attention for prolonged or worsening symptoms.

In the UK, reports show a steady increase in HMPV cases since October 2024. Although specific numbers are not published, data from the UK Health and Security Agency indicates that while there has been a rise in cases, this aligns with typical seasonal trends. The agency reassures that the current situation does not indicate any deviation from expected patterns.

HMPV Trends in China and Globally

In China, recent media reports suggested hospitals were overwhelmed by a surge in HMPV cases. However, healthcare professionals in major hospitals, including the Children’s Hospital affiliated with the Capital Institute of Pediatrics and the China-Japan Friendship Hospital, have clarified that the majority of their cases are influenza-related. While there is a slight uptick in HMPV cases compared to previous years, it remains substantially less than the influenza cases. This winter, as in other countries in the northern hemisphere such as the US, the increased prevalence of HMPV is typical of seasonal respiratory virus trends.

The World Health Organization (WHO) reassures that the reported levels of acute respiratory infections, including HMPV, in China and other northern hemisphere countries, are within the expected range for the winter season. There have been no emergency declarations as a result of HMPV, and Chinese authorities confirm that the healthcare system is managing the current patient load effectively.

Likelihood of a Covid-style Pandemic from HMPV

Health experts assert that the fears of HMPV developing into a pandemic similar to Covid-19 are unfounded. As HMPV has been present worldwide for decades, there exists a degree of population immunity due to previous​ exposures. Almost every child will experience at least one HMPV infection by their fifth birthday, leading to multiple reinfections throughout life. According to Dr. Paul Hunter, a medical professor at the University of East Anglia, there are no signs indicating HMPV could lead to a more serious global health crisis.

A note from PP Health Malaysia

The global focus on HMPV, especially during the winter months, stems from its similarity to other respiratory viruses and the general heightened awareness of such infections post-Covid-19. However, the current data and expert opinions suggest that while vigilance and preventive measures are essential, there is no cause for alarm regarding the potential of HMPV to cause a crisis of pandemic proportions. By maintaining good hygiene practices and being vigilant about symptoms, individuals can protect themselves and others from HMPV and other respiratory illnesses.