About Human Metapneumovirus

Overview

HMPV can cause upper and lower respiratory illness in people of all ages, especially in young children, older adults, and people with weakened immune systems.

Discovered in 2001, HMPV is in the Pneumoviridae family like respiratory syncytial virus (RSV). Broader use of molecular diagnostic testing has increased identification and awareness of HMPV as a cause of upper and lower respiratory infection.

Symptoms

Symptoms commonly associated with HMPV include cough, fever, nasal congestion, and shortness of breath. In some people, these symptoms may progress to bronchitis or pneumonia. The symptoms of HMPV can be similar to symptoms from other viruses that cause upper and lower respiratory infections.

Complications

People can get HMPV infections any time of the year, but infections are most common during winter through spring.

More severe illness is less common but can include:

• Asthma attack and reactive airway disease (wheezing, difficulty breathing)

• Middle ear infections (infection behind the ear drum)

• Bronchiolitis (infection of the small airways)

• Croup ("barking" cough)

• Fever

In adults, infection with HMPV may complicate chronic obstructive pulmonary disease (COPD). Pneumonia may occur in older adults as well as people with weakened immune systems.

You may have multiple HMPV illnesses throughout your lifetime.

How it spreads

HMPV most likely spreads from an infected person to others through:

• the air by coughing and sneezing

• close personal contact, such as touching or shaking hands

• touching objects or surfaces that have the viruses on them, then touching the mouth, nose, or eyes

In the U.S., HMPV circulates in predictable patterns each year, typically beginning in winter and lasting through spring.

Surveillance and Seasonality

Surveillance data from the CDC's National Respiratory and Enteric Virus Surveillance System (NREVSS) show HMPV spreads during late winter and spring in mild climates in the continental U.S. HMPV, RSV, and influenza can circulate at the same time during the respiratory virus season.

Prevention

There is no vaccine or treatment that can prevent HMPV infection. To prevent the spread of HMPV, follow core prevention strategies for respiratory viruses.

• Practice good hygiene (practices that improve cleanliness).
  • Cover your mouth and nose with a tissue when you cough or sneeze. If you don't have a tissue, cough or sneeze into your elbow, not your hands.
  • Learn and use proper handwashing techniques. Frequent handwashing is especially important in childcare settings and healthcare facilities.
  • Clean frequently touched surfaces, such as countertops, handrails, and doorknobs, regularly.

• Take steps for cleaner air.

• When you have symptoms of a respiratory virus, take steps to prevent spread.

In healthcare settings, healthcare providers should follow CDC's Isolation Precautions Guideline.

Testing and diagnosis

Since there are no treatments for HMPV, healthcare professionals may not routinely consider or test for HMPV. However, testing can help distinguish HMPV from other infections and guide decisions about isolating, antibiotic use, and need for more testing. In people with severe illness, testing for HMPV can detect both viruses and bacteria. Healthcare professionals should consider HMPV testing during winter and spring when HMPV infections are most common.

Infection with HMPV can usually be confirmed by:

• Molecular assays (nucleic acid amplification tests), which are preferred

• Antigen tests (including rapid diagnostic tests and immunofluorescent assays)

Treatment

Currently, there is no specific antiviral therapy to treat HMPV and no vaccine to prevent HMPV. Medical care is supportive, and most people will recover on their own. If you get sick, you should:

• drink plenty of liquids

• stay home and rest

Resources

• National Respiratory and Enteric Virus Surveillance System (NREVSS)