HMPV (Human Metapneumovirus): Your Questions Answered

In the not-too-distant past, a stuffy nose and cough usually signaled what was simply called the common cold, and few people concerned themselves with the virus behind it.

That’s understandable, considering that most people have never heard of the more than 200 viruses that can cause the common cold, including rhinovirus and one that’s been in the news lately: human metapneumovirus (HMPV).

HMPV is a common respiratory virus, and news reports have been following the rising number of cases in various parts of the world, including the United States. However, HMPV is nothing to panic about and is something most people have already been exposed to in their lives, says Scott Roberts, MD, a Yale Medicine infectious diseases specialist. Typically, HMPV causes a mild upper respiratory infection, but it can also affect the lower respiratory tract and be more serious for infants and people who are immunocompromised.

“HMPV has been around for at least 50 years, but it is increasingly identified as a cause of respiratory viral infections since we have gotten better at testing in general,” Dr. Roberts says. “Almost all children have had an HMPV infection by the age of 5. But like all viruses, there are usually different strains and mutations from season to season, which can lead to repeat infection, especially if it has been a while since the last infection.”

HMPV belongs to the same virus family as RSV (respiratory syncytial virus). Both HMPV and RSV are among the many viruses that affect the upper and lower respiratory tracts. HMPV and RSV share a collection of symptoms, including cough, fever, nasal congestion, and shortness of breath.

“RSV is classically thought of as more common than HPMV, but HPMV is much less studied than RSV,” Dr. Roberts says. “It can be hard to distinguish an HPMV infection from any other respiratory virus infection, most notably RSV.”

An HMPV infection is usually mild and resolves within about six days; however, infants, older adults, and those who are immunocompromised or have conditions such as chronic obstructive pulmonary disease (COPD) or asthma are at higher risk for more serious illness, including pneumonia.

There are some known differences between RSV and HMPV. In general, RSV is more prevalent, so the incidence of infection in infants is higher as a result, and it is a common cause of hospitalization in infants.

And, in the U.S., HMPV generally circulates in the late winter through spring, whereas RSV, most recently, has been more common in the fall and early winter, Dr. Roberts says.

Like other respiratory viruses, HMPV spreads via inhaled aerosol droplets from an infected person’s coughs or sneezes. It can also be transmitted through personal contact, including touching or shaking hands with an infected individual or by touching contaminated objects or surfaces, such as doorknobs and elevator buttons, and then touching your mouth, nose, or eyes.

Prevention methods include washing your hands with soap and water for at least 20 seconds; avoiding touching your eyes, nose, or mouth with unwashed hands; and maintaining a physical distance from sick people for at least a week after their symptoms appear. Wearing a mask can also help protect from infection.

HMPV is not included in the rapid tests used in doctor’s offices that typically look for flu, COVID-19, and RSV. “Because there is no specific treatment, meaning there’s nothing we can give someone if their test is positive, it often isn’t tested for,” Dr. Roberts says. “The respiratory viral panels in the hospital, however, often have HMPV on it.”

Treatment is “supportive care,” Dr. Roberts says, which includes resting and drinking plenty of fluids.

While there are vaccines and treatments for COVID-19 and for RSV, there is not one for HMPV. “A few are in development phase,” Dr. Roberts says.

“I would treat HMPV as I would RSV, where most everyone will have mild respiratory symptoms that will improve,” Dr. Roberts says. “I would take precautions and preventative measures if I or someone near me is high-risk, and there is a need to prevent exposure, such as having a newborn in the household. Otherwise, I would not be worried.”