Human metapneumovirus (HMPV), first identified in 2001, is a common respiratory virus affecting individuals of all ages, although its impact varies significantly. While reinfection is possible throughout life, initial exposure typically occurs in early childhood, with virtually all children encountering the virus by the age of five. HMPV’s clinical presentation ranges from mild, cold-like symptoms to severe respiratory illness, particularly in vulnerable populations like infants, young children, the elderly, and individuals with compromised immune systems or underlying health conditions. The virus spreads through respiratory droplets produced during coughing and sneezing, similar to other common respiratory viruses. Seasonal peaks of HMPV infections occur during winter and spring in the Northern Hemisphere and June and July in the Southern Hemisphere.
HMPV infection commonly manifests as mild flu-like symptoms, including fever, cough, runny nose, and sore throat, typically resolving within 5-7 days with outpatient care. However, in younger children, particularly those under five, HMPV can lead to more severe manifestations, such as bronchiolitis, pneumonia, and even Acute Respiratory Distress Syndrome (ARDS), necessitating hospitalization and potentially intensive medical interventions. Estimates suggest that HMPV accounts for 3-10% of pediatric hospital admissions for respiratory illness. In these severe cases, symptoms often include high-grade fever, significant respiratory distress, and wheezing.
Diagnosing HMPV solely based on clinical symptoms presents a challenge due to its similarity to other respiratory viruses like RSV and influenza. Accurate diagnosis relies on laboratory testing, with polymerase chain reaction (PCR) analysis of nasopharyngeal secretions considered the gold standard for detecting HMPV RNA. Surveillance systems, such as those implemented by the Indian Council of Medical Research (ICMR) and the Integrated Disease Surveillance Programme (IDSP), routinely screen for respiratory viruses, including HMPV, to monitor its prevalence and potential outbreaks.
Currently, no specific antiviral treatment exists for HMPV. Management primarily focuses on alleviating symptoms and providing supportive care. Common interventions include antipyretics to reduce fever and antihistamines to manage congestion and other related symptoms. Hospitalized children may require supplemental oxygen, nebulizer treatments, and, in severe cases, mechanical ventilation to support their breathing. The absence of targeted antiviral therapies underscores the importance of preventive measures and supportive care in managing HMPV infections.
Prevention of HMPV transmission relies on adopting standard hygiene practices effective against many respiratory viruses. Frequent handwashing with soap and water for at least 30 seconds remains a cornerstone of prevention. Respiratory etiquette, including covering the mouth and nose while coughing or sneezing and wearing a mask, can significantly limit the spread of respiratory droplets. Avoiding close contact with infected individuals and regularly disinfecting frequently touched surfaces further contribute to reducing transmission risk. The development of a vaccine against HMPV remains a research priority.
While both HMPV and COVID-19 can cause mild respiratory symptoms, crucial distinctions exist. COVID-19 exhibits a wider range of symptoms, potentially affecting multiple organ systems, and carries a higher risk of severe complications. HMPV primarily affects the respiratory system, and although serious complications can occur, they are generally less frequent and severe than those observed in COVID-19. Data collected at Aster RV Hospital over three years revealed that out of 291 nasopharyngeal samples collected from hospitalized children with acute respiratory infections, 5.8% tested positive for HMPV. Among these HMPV-positive cases, 35% required some form of oxygen therapy, and more than 50% had co-infections with other respiratory viruses, highlighting the potential for complex interactions between respiratory pathogens. The ongoing surveillance and research on HMPV are essential to improve diagnostic capabilities, develop effective treatments, and ultimately prevent severe outcomes associated with this common respiratory virus.
