While the spotlight often shines on cold, flu, and COVID-19, a lesser-known but highly contagious virus is making significant waves on the West Coast. This virus, known as human metapneumovirus (HMPV), is spreading rapidly, particularly in Northern California cities such as San Francisco, Marin, Vallejo, Napa, Novato, Santa Rosa, Sacramento, and Davis, according to Wastewater SCAN data.

HMPV saw a dramatic increase in cases in January, and although the winter season surge is starting to decline, the virus’s levels remain notably high as of early March. The Centers for Disease Control and Prevention (CDC) indicates that symptoms typically experienced by healthy children and adults include cough, fever, nasal congestion, and shortness of breath.

Dr. Marc Siegel, a senior medical analyst for Fox News, explained to Fox News Digital that HMPV is a single-stranded RNA virus, similar to influenza and COVID-19. He noted, “The virus is increasing not only in the West but also across other regions of the country.”

Indeed, the data also reveals a sharp rise in HMPV cases in the Midwest and Northeast, suggesting that the virus is not confined to just one area but is a growing concern nationwide.

The wastewater data also show that HMPV is rising sharply in the Midwest and Northeast.

The most common symptoms of the virus in healthy children and adults include cough, fever, nasal congestion and shortness of breath, per the CDC.

Those at highest risk of severe illness, such as pneumonia, include young children, older adults and those who are immunocompromised. 

It leads to over 650,000 hospitalizations yearly worldwide, according to Siegel.

Rare effects of HMPV can include asthma attacks, wheezing, difficulty breathing, bronchiolitis (infection of the small airways), ear infections, croup (a “barking” cough) and fever, according to the CDC.

HMPV is in the same viral family as respiratory syncytial virus (RSV) and was first discovered in 2001, according to the Centers for Disease Control and Prevention.  

The National Wastewater Surveillance System (NWSS), part of the CDC, monitors samples of wastewater (sewage) for viruses and bacteria to detect infection patterns in communities.

Adults with COPD (chronic obstructive pulmonary disease) can experience complications of their illness if they contract HMPV. 

“It can worsen chronic lung conditions,” Siegel confirmed.

The virus can be transmitted from close personal contact and from coughing, sneezing and touching contaminated surfaces, per the CDC.

HMPV is most commonly reported from winter through spring.

There is no vaccine or treatment for the virus, the CDC notes, but HMPV can be diagnosed via testing by a healthcare provider. Supportive care includes drinking plenty of hydrating fluids and resting.

The agency provides the following prevention methods to help curb spread.

• Cover your mouth and nose with a tissue when coughing or sneezing
• Follow proper handwashing techniques
• Regularly sanitize frequently touched surfaces
• Avoid contact with others and/or wear a mask when sick