HMPV cases on the rise: Virus not new. Detected much before Covid-19 pandemic outbreak

Human Metapneumovirus (HMPV), a well-known respiratory virus, has recently gained attention following an outbreak in China. 

In India, two HMPV cases were recently reported in Karnataka as part of the routine surveillance by the Indian Council of Medical Research (ICMR). While this has raised concerns about a potential pandemic similar to COVID-19, experts have reassured the public that HMPV is not a new pathogen. It has been recognised worldwide, and the ICMR, along with the Integrated Disease Surveillance Programme (IDSP), monitors trends of respiratory illnesses, including HMPV, alongside other viruses like influenza and RSV. 

The government has emphasized the strength of its health infrastructure and surveillance systems, which remain vigilant in detecting and addressing emerging health threats. Hospitals and healthcare providers have been instructed to report cases of Influenza-like Illness (ILI) and Severe Acute Respiratory Infection (SARI) through the Integrated Health Information Platform (IHIP), with an increased focus on strict monitoring, documentation, and isolation protocols. 

What is HMPV? 

HMPV is a respiratory virus that affects individuals of all ages. First identified in 2001, it belongs to the Paramyxoviridae family and is closely related to Respiratory Syncytial Virus (RSV). HMPV is transmitted through respiratory droplets from coughing or sneezing and by touching contaminated surfaces or coming into direct contact with infected individuals. 

HMPV can cause a range of illnesses, from mild respiratory discomfort to severe complications, especially in vulnerable populations such as infants, the elderly, and those with weakened immune systems. The virus is common worldwide and typically peaks during late winter and early spring in temperate regions, though it circulates year-round in certain areas. 

Symptoms of HMPV 

HMPV symptoms can vary depending on a person’s age, overall health, and immune response. Mild cases usually include a runny nose, sore throat, cough, and fever—similar to a common cold. Moderate cases may present with persistent cough, wheezing, and fatigue. 

In more severe instances, particularly in infants, older adults, or individuals with chronic illnesses, HMPV can lead to complications like bronchitis, bronchiolitis, or pneumonia. Severe Acute Respiratory Illness (SARI) may also occur, requiring hospitalization, especially in high-risk groups. 

Duration of the infection 

Mild cases of HMPV generally last a few days to a week, while severe cases may take longer to recover. Persistent symptoms, such as a cough, may linger longer. Diagnosing HMPV based on symptoms alone can be challenging, as it shares similarities with other respiratory infections like RSV and influenza. The gold standard for diagnosis is Reverse Transcription Polymerase Chain Reaction (RT-PCR), though antigen detection assays can provide faster results. 

Treatment for HMPV 

Currently, no specific antiviral treatment or vaccine exists for HMPV. Management is supportive, depending on the severity of the infection. Mild cases can be treated with rest, hydration, and over-the-counter medications to alleviate fever and congestion. Severe cases, such as pneumonia or bronchiolitis, may require oxygen therapy and hospitalization, with mechanical ventilation in cases of severe respiratory distress. Research is ongoing to develop antiviral treatments and vaccines, but early medical intervention and preventive measures are essential to managing HMPV infections. 

Comparison between HMPV & COVID-19 

While both HMPV and COVID-19 (caused by the SARS-CoV-2 virus) are respiratory pathogens, they differ significantly in their virology, transmission, and public health impact. 

Both viruses spread through respiratory droplets, direct contact, and contaminated surfaces. They can cause mild to severe respiratory symptoms like cough, fever, and shortness of breath, and are particularly harmful to vulnerable populations, including infants, the elderly, and those with weakened immune systems. 

However, COVID-19 presents a broader range of symptoms, such as loss of taste and smell, and carries a higher risk of severe complications like blood clotting and multi-organ failure. Additionally, vaccines and antiviral treatments are available for COVID-19, whereas HMPV currently only has supportive care available for management.