What is human metapneumovirus? What to know about the virus that flew under everyone's radar.

All eyes were on viruses like influenza and RSV this winter season, but Americans may have missed another important pathogen: Human metapneumovirus, or hMPV.

The Centers for Disease Control and Prevention last week reported an uptick of hMPV cases throughout the country this winter and spring, which experts say may be partly due to the public's increased capacity to test for different viruses.

“There’s a much greater attention to identifying the cause of (infections) than we’ve ever had before,” said Dr. Rick Malley, an infectious disease specialist at Boston Children’s Hospital.

He attributed that increased attention to the COVID-19 pandemic.

“The importance of other viruses and the diseases they cause has come to the floor and that’s why I think you’re hearing more about this virus," he said.

Here's everything to know about the respiratory virus that flew under everyone's radar this season, including symptoms, transmission and treatment.

What is human metapneumovirus, hMPV?

Human metapneumovirus, or hMPV, is an infection that affects the upper and respiratory tract, according to the CDC. While it can affect people of all ages, the agency says young children, older adults and people with weakened immune systems are at greater risk.

HMPV was first discovered in 2001 and belongs to the Pneumoviridae family, which also includes respiratory syncytial virus, the CDC said.

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Is human metapneumovirus just a cold? What are hMPV symptoms?

People with hMPV typically experience mild symptoms similar to a cold, according to the American Lung Association. Symptoms last about two to five days and usually resolve on their own in healthy individuals.

The CDC says common symptoms include:

• Cough

• Fever

• Nasal congestion

• Shortness of breath