HMPV Cases Rising: Symptoms, Spread & Prevention of This RSV-Like Virus

Cases of Human Metapneumovirus (HMPV) are increasing across the United States, with concentrations detected in California and Latest Jersey, according to recent reports. Wastewater surveillance data from California revealed high levels of the virus in areas including San Francisco, Sacramento, Napa, Davis, Vallejo and San Francisco.

HMPV, a respiratory virus in the same family as RSV, can cause both upper and lower respiratory illness, particularly in vulnerable populations. The Centers for Disease Control and Prevention (CDC) notes that young children, older adults, and individuals with compromised immune systems are at the highest risk of severe illness.

Symptoms of HMPV closely mirror those of other respiratory infections, including cough, fever, nasal congestion, and shortness of breath. In some cases, these symptoms can escalate to bronchitis and pneumonia, according to the CDC. The virus spreads through respiratory droplets produced by coughing and sneezing, close personal contact, and by touching contaminated surfaces before touching the face.

While HMPV typically circulates in the U.S. From winter through spring, the current surge is contributing to increased demand on healthcare resources, alongside ongoing cases of COVID-19, RSV, and influenza. The New Jersey Respiratory Surveillance Report indicated that approximately 4 percent of residents tested were positive for HMPV as of March 10, 2026.

Currently, there is no specific antiviral treatment or vaccine available for HMPV. The CDC recommends preventative measures such as covering coughs and sneezes, frequent handwashing, and cleaning frequently touched surfaces. Most individuals recover from HMPV with rest and adequate hydration.

Testing for HMPV is not routinely performed due to the lack of specific treatment options, but can be conducted using nasal or throat swabs to aid in clinical decision-making regarding isolation and further testing, according to the CDC. Severe cases of HMPV can lead to complications such as asthma attacks, middle ear infections, bronchiolitis, croup, and fever. Individuals with chronic obstructive pulmonary disease are also susceptible to complications, and older adults and those with weakened immune systems may develop pneumonia.

Dean Blumberg, chief of pediatric infectious diseases at UC Davis Health, noted that HMPV causes symptoms “very similar to RSV,” and that infants and young children under two years of age are most at risk for complications like bronchiolitis. Children with pre-existing heart or lung conditions, or weakened immune systems, face an even higher risk of severe illness.