Outbreak: Why is HMPV in the news?

The chilling winds of winter in northern China have brought with them a surge in cases of human metapneumovirus (HMPV), a respiratory virus often overshadowed by its flashier cousins like RSV and influenza. 

Chinese media have reported a rise in HMPV infections.

With hospitals bracing for a wave of patients and social media rife with doomsday predictions, the question looms: Is HMPV the next global health threat?

There’s no treatment or vaccine specifically developed against HMPV.

A familiar yet stealthy foe

HMPV was first identified in 2001, and is a well-studied virus, based on research listings from Nature and Science Direct.

Since then, HMPV has been recognised as an important cause of upper and lower respiratory disease in all ages.

Infection occurs early in life and reinfection is common, studies show.

Prior to 2001, it has likely been circulating globally for decades – hidden behind its non-specific symptoms. 

Symptoms

It causes cold- and flu-like illnesses, with symptoms such as:

Social media is in a frenzy, flooded with ominous doomsday warnings about HMPV.

Panic ripples through digital corridors as speculation runs wild. But amid the wild speculation, experts from the US National Institutes of Health's National Library of Medicine (NIH/NLM) stepped forward, determined to quell the growing hysteria and soothe frayed nerves.

Key studies on the virus gives a dose of reality.

Writing in 2021 in the journal Advances in Clinical Radiology, researchers Dr Jennifer Ann Febbo and Dr Loren Ketai offer key points:

First: Symptoms of HMPV infection "overlap" with those of other respiratory infections including RSV. 

Second: Children most commonly present with cough, fever and rhinorrhea, but may also develop croup, asthma exacerbation, bronchiolitis and pneumonia.

"Disease may be severe in immunocompromised individuals including stem cell transplant recipients and patients being treated for malignancy, with reports of pneumonia," they pointed out.

“HMPV has been detected in up to 25 per cent of cases of community-acquired viral pneumonia and is an important cause of hospitalisation in adults over the age of 65.”

Third: Fatalities are "rare", the researchers added.

Treatment: Treatment is mainly supportive, although ribavirin may be used in severely ill patients.

'Not a new virus'

China’s Center for Disease Control and Prevention (CDC) emphasizes HMPV is not a novel virus.

“For most, symptoms subside within a week,” reassures virologist Zheng Lishu, who works at the Institute of Virology at the China CDC.

Beijing-based CGTN confirmed that China has seen a rise in HMPV cases of since mid-December 2024.

Chinese domestic media outlets have reported an increase in HMPV infections, with some individuals describing “flu-like” symptoms.

This comes after the US also saw a surge in HMPV cases around April 2024, with media outlets at the time labelling it “little-known”.

“For most people, the symptoms will gradually subside in about a week,” Zheng said.

Caution against self-diagnosis 

Another Chinese medical expert advised people to seek medical attention, and against self-diagnosis.
Ruan Zhengshang, deputy head of the department of infectious diseases at Xinhua Hospital in Shanghai, cautioned against self-diagnosing of HMPV based on symptoms like fever or dizziness. 

He noted that HMPV shares similar symptoms with other respiratory illnesses, including cough, nasal congestion, fatigue, gastrointestinal discomfort and even high fever.

What’s behind the surge?

The uptick in cases has triggered concern, but experts point to two culprits: improved detection technologies and heightened public vigilance. 

“We’re just more cautious of outbreaks now,” says Dr. Jacqueline Stephens of Flinders University. The scars of the COVID-19 pandemic have left the world on edge, where even a whisper of an unfamiliar name like “metapneumovirus” sets off alarms.

Chinese officials, however, are tamping down fears. 

“The diseases this season appear less severe and more localized compared to last year,” foreign ministry spokesperson Mao Ning stated, urging the public to remain calm.

No cure, no vaccine — but no need to panic

Unlike COVID-19, HMPV is no stranger to the human immune system. 

Most people recover with rest and supportive care, such as hydration, light meals, and monitoring for worsening symptoms. However, for the vulnerable — children, the elderly, and those with weakened immune systems — close observation is critical.

“There’s no vaccine or antiviral treatment for HMPV yet,” notes Prof. Paul Griffin of Mater Health Services. 

“But the situation is far from pandemic-level. Education and simple precautions can reduce transmission.”

Lessons from the pandemic

While the world may not need to dust off its lockdown playbook, the surge in HMPV cases serves as a stark reminder of the basics. 

Experts urge consistent handwashing, good ventilation, and staying home if you’re sick. 

Masks, once a controversial symbol of the COVID-19 era, are again being recommended in crowded or high-risk areas.

“We’ve let our guard down post-pandemic,” Griffin observes. “But simple measures can keep us all healthier this winter.”

Takeaway: A winter storm, not a cataclysm

HMPV’s resurgence is no apocalypse, but it’s a sobering wake-up call to the enduring power of respiratory viruses. 

For now, vigilance — not panic — is the order of the day. After all, the virus may not be new, but neither are humanity’s tools to combat it: knowledge, preparation, and a little common sense.

In May 2023, the US CDC reported a rise in human metapneumovirus (HMPV) infections. However, viral posts on Chinese social media claimed HMPV had a "43% mortality rate", citing a small, outdated study.

These posts misrepresented the findings, which focused on patients with severe underlying conditions, not the general population, according to an AFP Fact Check:

Key Facts:

Context:
While HMPV cases rose in the US during spring, and in Asia (China, India, Japan) in the current winter, the claims of a "high mortality rate" created unnecessary alarm, though it lacks scientific backing.

Fact-checkers, including AFP, confirmed these assertions are misleading. This highlights the importance of critical evaluation of health claims on social media.