HMPV Cases Rise in China and U.S. During Respiratory Virus Season

Chinese health officials are monitoring a surge in human metapneumovirus (HMPV) cases, a common respiratory virus that peaks during winter months. The World Health Organization (WHO) confirmed the rise in acute respiratory infections in China but noted that the overall intensity of respiratory illnesses this year is lower than in 2023. In the U.S., HMPV cases have also increased, with 1.94% of weekly tests positive as of late December 2024, according to the Centers for Disease Control and Prevention (CDC).

HMPV, first identified in 2001, is part of the Pneumoviridae family, which includes respiratory syncytial virus (RSV). It causes symptoms such as cough, nasal congestion, fever, and shortness of breath. While most cases are mild, young children, older adults, and immunocompromised individuals are at higher risk of severe complications like bronchitis or pneumonia.

Dr. William Schaffner, a professor of preventive medicine at Vanderbilt University Medical Center, told ABC News that HMPV is a well-known virus that circulates during the respiratory virus season. “All of these respiratory viruses—influenza, COVID, RSV, human metapneumovirus—increase this time of the year, in part because we get so close to each other,” he said.

HMPV spreads through respiratory secretions, close personal contact, and contaminated surfaces. In the U.S., cases typically rise in winter and decline in spring. Dr. Peter Chin-Hong, an infectious diseases specialist at the University of California, San Francisco, noted that most people are exposed to HMPV by age five, and reinfections are usually milder.

There is no specific treatment or vaccine for HMPV. Supportive care, such as hydration, fever reduction, and bronchodilators for wheezing, is the standard approach. Public health experts recommend basic hygiene practices, including handwashing and covering coughs, to prevent transmission. Vaccination against other respiratory viruses like COVID-19, flu, and RSV is also advised to reduce the risk of co-infections.

Despite the rise in cases, experts emphasize that HMPV is not a novel pathogen and does not pose a pandemic threat. Dr. Paul Hunter, a medical professor at the University of East Anglia, stated, “Almost every child will have at least one infection with HMPV by their fifth birthday, and we can expect to have multiple reinfections throughout life.”