A Comprehensive Review on Human Metapneumovirus

Background: Human metapneumovirus (HMPV) is a respiratory virus that presents symptoms similar to those of the common cold or influenza, including cough, nasal congestion, sore throat, fever, wheezing, and shortness of breath. The primary mode of transmission is through respiratory droplets from an infected person’s cough or sneeze, as well as through contact with contaminated surfaces. HMPV was first recognized in 2001 and poses a significant public health concern, particularly affecting vulnerable groups like children, the elderly, and those with weakened immune systems. Its impact is notably severe in children under five years, contributing to rates of infant mortality. The main goal of the review article is to improve public health by gathering vital information on the human metapneumovirus (HMPV) and how it affects respiratory illnesses. It seeks to advance knowledge of these illnesses and methods of response. Methods: A thorough literature search was performed utilizing databases concentrating on studies published up to May 2025. The selection criteria were based on comprehensive prior research concerning human metapneumovirus on a global scale. Result: HMPV (Human Metapneumovirus) undergoes gradual mutations, leading to the emergence of new strains that are derived from previously circulating variants. Clinical features associated with different HMPV genotypes exhibit moderate variations, indicating some diversity in how the virus presents in patients. Notably, no significant seasonal trends have been observed in the incidence of HMPV infections, suggesting that the virus does not follow typical seasonal patterns seen with other respiratory viruses. In terms of severity, HMPV infections are generally less severe compared to those caused by Human Respiratory Syncytial Virus (HRSV). However, co-infection with both HMPV and RSV in young children has been linked to more severe illness than infections with either virus alone, highlighting the potential for compounded health risks in this demographic. Additionally, children hospitalized with HMPV are at an increased risk of developing acute kidney injury (AKI), with this risk correlating with age, independent of the severity of respiratory symptoms or existing comorbidities. Despite a significant increase in testing for respiratory viruses during the COVID-19 pandemic, the overall incidence of HMPV has remained stable, indicating that the pandemic did not lead to a surge in HMPV cases. Discussion: The evolutionary path of HMPV, marked by gradual mutations derived from earlier strains, restricts its ability to cause widespread pandemics. This view is supported by the lack of notable seasonal fluctuations and generally milder clinical impact compared to HRSV. Nonetheless, the rise in severity observed during co-infections highlights the need for accurate diagnosis and thorough monitoring. Many individuals’ pre-existing immunity may help lessen the effects of new HMPV infections, indicating that targeted vaccines or immune-boosting approaches could be beneficial. Additionally, the surprising link between HMPV and acute kidney injury, particularly in older children, calls for more research into its non-respiratory complications. The stable infection rates during the pandemic, despite increased testing efforts, suggest that the virus’s transmission patterns remain consistent. Conclusion: HMPV is less researched compared to other respiratory viruses, raising concerns about its management. The necessity of routine HMPV testing is highlighted alongside the need for further research to improve treatment and prevention strategies. Despite advancements in understanding the virus, significant challenges remain in deciphering its mechanisms and developing effective therapeutics. There is an urgent need for targeted antivirals and vaccines for at-risk populations, along with comprehensive data on HMPV-related diseases to guide future research and interventions.