The HMPV outbreak is an ongoing surge in cases of the human metapneumovirus in 2024. It began when the Chinese Center for Disease Control and Prevention published data showing that respiratory infections of human metapneumovirus had risen significantly in the week of 16 to 22 December 2024.[1] As of 2006[update], hMPV had a worldwide distribution and had been identified on every continent.[2][dubious – discuss]
Epidemiology
In late 2024, human metapneumovirus was linked to 6.2 percent of positive respiratory illness tests and 5.4 percent of respiratory-illness hospitalizations in China, more than COVID-19, rhinovirus or adenovirus.[3][better source needed] Cases were reported in Hong Kong, with a lower growth rate than that of mainland China.[4][5] Cases were reported in Malaysia, with an increase of 102 cases from 225 cases in 2023 to 327 cases in 2024.[6][7]India confirmed its first cases of HMPV in Bengaluru on 6 January 2025. An 8-month-old boy and a 3-month-old girl were diagnosed after experiencing respiratory symptoms.[8]
Chinese health officials stated that the surge was consistent with overall seasonal trends, and officials in Taiwan and India stated that the very young, old, and immunocompromised were the most at risk,[10][11] which is a known characteristic of HMPV.
No conclusive studies have proven the true method of transmission, its likely through contract with contaminated secretions, via droplet, aerosol, or fomite vectors.
Cause
The genomic organisation of HMPV is similar to RSV.
Diagnosis
RT-PCR has been extensively used for pathogen detection, while this method is not appropriate for early HMPV diagnosis because of its low sensitivity. The RT-qPCR method has a higher sensitivity than the traditional RT-PCR, and requires less operation time and fewer equipment, thus RT-qPCR has been widely used for the timely molecular detection of HMPV.[16] The usage of bronchoscopy and chest X-rays are also prevalent.[17] It can also be diagnosed through direct detection of viral genome by nucleic acid amplification test (NAAT), and direct detection of viral antigens in respiratory secretions using immunofluorescence or enzyme immunoassay.[18]
HMPV does not have a specific antiviral medication. Treatment primarily aims at managing symptoms and preventing complications.[20] Rest and hydration, over-the-counter medications to control body-aches and fevers are recommended for mild conditions, while some cases may require oxygen therapy and hospitalization.[20] Severe cases of hMPV as with individuals who are immunocompromised are treated with Ribavirin and IVIG.[21][22]
Prognosis and Risk factors
Most people recover from HMPV in about 7 to 10 days without any complications. However, certain groups face a higher risk of severe complications:
