Human metapneumovirus (HMPV), a respiratory pathogen first identified in 2001, has recently garnered attention due to a surge in cases in China and the confirmation of infections in India. While HMPV typically causes mild respiratory illnesses, it can lead to severe complications in vulnerable populations, including infants, the elderly, and individuals with compromised immune systems.
Current status in India
As of January 2025, India has reported its first confirmed cases of HMPV. The Indian Council of Medical Research (ICMR) has identified seven cases across the country, including two infants in Bengaluru and a two-month-old boy in Ahmedabad. These cases have raised public concern, especially in light of reports from China where a surge in HMPV infections has overwhelmed hospitals. However, Indian health officials emphasize that there is no direct linkage between the cases in India and those in China. The Union Health Ministry has stated that HMPV is not a new virus and has been previously detected in India, including Kerala. They urge the public to avoid spreading panic or misinformation about the virus.
Understanding HMPV
HMPV is a recently identified single-stranded RNA virus in the Paramyxoviridae family, linked to bronchiolitis, pneumonia, and the worsening of asthma symptoms. It typically causes seasonal outbreaks during late winter to spring and spreads through respiratory droplets, direct contact with secretions, or contaminated surfaces, with an average incubation period of 5–6 days. Clinical presentations range from mild symptoms, such as cough, rhinorrhea, fever, and malaise, to severe conditions, including bronchiolitis, pneumonia, asthma or COPD exacerbations, and acute respiratory distress syndrome (ARDS), particularly in high-risk groups like infants, the elderly, and individuals with chronic or immunocompromising conditions.
A study by Chang et al. provided insights into the initial steps of HMPV infection. The researchers found that the virus first binds to host cells through interactions between its fusion (F) protein and heparan sulfate, a glycosaminoglycan present on the cell surface. This binding facilitates the virus’s entry into the cell, marking a crucial step in the infection process.
Preventive measures
Currently, there is no specific antiviral treatment or vaccine available for HMPV. Preventive measures are crucial to control the spread of the virus. Health experts recommend the following precautions:
- Hand hygiene: Regular and thorough hand washing with soap and water is essential. In situations where soap and water are not available, using an alcohol-based hand sanitizer is advisable.
- Respiratory etiquette: Covering the mouth and nose with a tissue or the elbow when coughing or sneezing helps prevent the spread of respiratory droplets. Used tissues should be disposed of immediately, followed by hand washing.
- Avoiding close contact: Maintaining a safe distance from individuals exhibiting symptoms of respiratory illness is recommended. Avoiding crowded places, especially during peak seasons of respiratory infections, can reduce the risk of exposure.
- Surface disinfection: Regularly cleaning and disinfecting frequently touched surfaces, such as doorknobs, mobile devices, and countertops, can help eliminate the virus from the environment.
- Use of masks: Wearing masks, particularly in crowded or enclosed spaces, can reduce the transmission of respiratory viruses, including HMPV. This practice is especially important for individuals who are symptomatic to prevent spreading the virus to others.
Research indicates that HMPV is a significant contributor to respiratory illnesses globally. Several studies have indicated that HMPV has been circulating in human populations for over a century, with seasonal outbreaks typically occurring in the winter and early spring months.
Another study highlights the importance of infection control measures in healthcare settings to prevent nosocomial infections. The use of droplet isolation and strict hand hygiene protocols have been effective in controlling the spread of HMPV in hospitals and long-term care facilities.
Diagnosis and treatment
Diagnosis is often based on clinical presentation during seasonal peaks, with confirmation through laboratory tests such as reverse transcription polymerase chain reaction (RT-PCR), the gold standard for detecting HMPV. Rapid antigen tests and serology are also used but have limitations in sensitivity and timing. Treatment remains supportive, focusing on hydration, antipyretics, and oxygen therapy for hypoxia, with mechanical ventilation required in severe cases. There is no specific antiviral therapy, and antibiotics should only be used if a secondary bacterial infection is suspected.
Conclusion
While the emergence of HMPV cases in India warrants attention, health authorities advise against panic. There are no licensed vaccines yet, and clinicians should consider HMPV in the differential diagnosis of viral respiratory infections, particularly during outbreaks, and closely monitor high-risk patients to reduce progression to severe disease. By adhering to recommended preventive measures and staying informed through credible sources, individuals can protect themselves and their communities from HMPV and other respiratory infections.
References
- Haas LEM, Thijsen SFT, van Elden L, Heemstra KA. Human Metapneumovirus in Adults. Viruses. 2013 Jan 8;5(1):87–110.
- The Economic Times [Internet]. [cited 2025 Jan 8]. HMPV Virus Cases News Updates: Jharkhand health minister says state still unaffected by HMPV, says no need to panic. Available from: https://economictimes.indiatimes.com/news/newsblogs/hmpv-virus-cases-tracker-live-updates-human-metapneumovirus-news-symptoms-prevention-guidelines-bengaluru-gujarat/liveblog/116989837.cms
- Hamelin MÈ, Prince GA, Gomez AM, Kinkead R, Boivin G. Human Metapneumovirus Infection Induces Long-Term Pulmonary Inflammation Associated with Airway Obstruction and Hyperresponsiveness in Mice. The Journal of Infectious Diseases. 2006 Jun 15;193(12):1634–42.
- Chang A, Masante C, Buchholz UJ, Dutch RE. Human Metapneumovirus (HMPV) Binding and Infection Are Mediated by Interactions between the HMPV Fusion Protein and Heparan Sulfate. J Virol. 2012 Mar;86(6):3230–43.
- CDC. Human Metapneumovirus. 2024 [cited 2025 Jan 8]. About Human Metapneumovirus. Available from: https://www.cdc.gov/human-metapneumovirus/about/index.html