Mirna Fahmy

A two decade old HMPV virus is getting concerns because its cases has risen recently in China.

China is currently facing a surge in cases of human metapneumovirus (HMPV), a respiratory virus that has raised public health concerns reminiscent of the early days of the COVID-19 pandemic that erupted from Wuhan city, China, in December 2019.

According to New Delhi Television (NDTV), the number of cases has dramatically increased since late December 2024 and into January 2025, overcrowding hospitals and raising public concerns about a potential health crisis akin to the COVID-19 pandemic.

HMPV cases have spiked particularly among children in northern provinces of China during this winter season. The symptoms of HMPV are similar to those of common respiratory infections, including cough, fever, nasal congestion, and fatigue. While typically mild, it can lead to severe complications like pneumonia in vulnerable populations such as infants and the elderly.

In response to the rising cases, Chinese health authorities have implemented emergency measures to monitor and manage the situation. However, the government has characterised this outbreak as a seasonal occurrence, with a spokesperson stating that respiratory infections generally peak in winter.

The World Health Organisation (WHO) has not declared a global health emergency regarding HMPV at this time. However, a recent social media post triggered a stir, whereas WHO advised anyone who is feeling unwell to stay at home and contact a closest medical center if needed.

The fear is overwhelming everyone on social media because no one wants to go over the lock-down days of Covid. These days were dull and depressing to many, especially when it was related to the economies of many individuals.

Health officials in China and neighbouring countries like India have urged calm, emphasising that HMPV is similar to other respiratory viruses and does not warrant panic.

Reports indicate that Hong Kong has confirmed a few cases of HMPV, while health officials in Cambodia and Taiwan are issuing warnings due to the virus’s potential risks.

The Nigeria Centre for Disease Control (NCDC) issued a statement on January 7, 2025, asserting that while there has been a surge in HMPV cases in China, it does not pose a public health threat in Nigeria.

Individual EU countries didn’t issue  specific public statements regarding HMPV though HMPV instances are also increasing in nations like England, where the test positivity rate increased from 2.29 percent a month earlier to 4.53% in late December 2024.

Western experts noted that while HMPV is spreading, it remains part of the typical seasonal pattern of respiratory viruses and does not currently present a significant global risk.

There is currently no vaccine or specific antiviral treatment for HMPV; management focuses on alleviating symptoms. Centres for Disease Control and Prevention (CDC) stated that the virus spreads through respiratory droplets and contact with contaminated surfaces, similar to other respiratory viruses.

How severe are the symptoms of HMPV compared to COVID-19?

HMPV and COVID-19 are both contagious respiratory illnesses that share several similarities in symptoms and transmission methods, but they differ in severity and potential complications.

CDC indicated that both HMPV and COVID-19 can cause symptoms such as cough, fever, nasal congestion, sore throat, and shortness of breath.

HMPV typically presents with mild symptoms resembling those of the flu or common cold, lasting about 2 to 5 days. Severe cases can lead to complications like bronchitis or pneumonia, particularly in vulnerable groups such as young children and the elderly.

In contrast, COVID-19 can cause a wider range of symptoms, including severe respiratory distress and loss of taste or smell, and can lead to serious complications such as acute respiratory distress syndrome (ARDS), multi-organ failure, and long COVID symptoms. Hospitalisation rates for COVID-19 are generally higher compared to HMPV.

How does HMPV impact children differently than adults?

Children, especially those under five years old, are more likely to experience severe symptoms from HMPV compared to adults, critically inciting clinical manifestations. HMPV is a leading cause of both upper and lower respiratory tract infections in children. Unlike adults, who may experience milder symptoms resembling a common cold, children often exhibit more pronounced respiratory distress and are rarely asymptomatic.

Wheezing and breathlessness symptoms are more prevalent in children with HMPV than in those with other respiratory infections like influenza.

High fever and poor feeding in infants, especially from 0-5 months, as they may show signs of dehydration due to difficulty feeding leading to a possibility of “hospitalisation.”. According to Oxford Academic, a significant proportion of HMPV-infected children require hospitalisation due to severe respiratory conditions like bronchiolitis and pneumonia. For instance, about 38% of infected children may need supplemental oxygen.

How long has HMPV been existing?

Not new but two decades old. The National Institute of Health (NIH) revealed that HMPV was discovered in 2001 in the Netherlands by a research team led by Bernadette G. van den Hoogen. The discovery was made while isolating viruses from respiratory secretions of 28 young children who were experiencing respiratory infections. The researchers utilised a technique called randomly primed PCR (RAP-PCR), which allowed them to identify the genetic sequences of this previously unknown virus, distinguishing it from other common respiratory viruses.

Initially, HMPV stood out because traditional testing methods could only detect known viruses; it was through molecular biology techniques that researchers could reveal its unique genetic characteristics. The close relationship between HMPV and avian metapneumovirus (AMPV) led to its naming as HMPV, indicating its identity as a metapneumovirus that infects humans.

Retrospective studies have shown that HMPV has likely been circulating among humans for at least 50 years prior to its formal identification, suggesting that it had been present in the population long before its discovery in 2001. This indicates a longer history of human exposure to the virus than previously understood, with nearly all children being infected by the age of five.

CDC noted that HMPV cases are normally high during winter and spring. In March 2024, cases surged across the U.S. There were 19.6% of antigen tests and 10.9% of PCR tests for HMPV that were positive in early and mid-March, as the CDC reported. The numbers are about 36% higher than before the pandemic.

The American medical centre UC Davis Health quoted a professor of emergency medicine and an expert in public health and testing for infectious diseases saying that “HMPV is not something most people need to worry about. It is another version of the common cold.”

UC Davis Health article and CDC report reinstated that the normal medical care can be supportive, similar to medicines given for cold, flu, and influenza.