Human metapneumovirus (HMPV) can cause upper and lower respiratory diseases in people of all ages, especially among young children, older adults, and people with weakened immune systems. Discovered in 2001, HMPV is in the paramyxovirus family along with respiratory syncytial virus (RSV). Broader use of molecular diagnostic testing has increased the identification and awareness of HMPV as an important cause of upper and lower respiratory infection.
Symptoms commonly associated with HMPV include cough, fever, nasal congestion, and shortness of breath. Clinical symptoms of HMPV infection may progress to bronchitis or pneumonia and are similar to other viruses that cause upper and lower respiratory infections. The estimated incubation period is 3 to 6 days, and the median duration of illness can vary depending upon severity but is similar to other respiratory infections caused by viruses
Surveillance and Seasonality
Surveillance data from CDC’s National Respiratory and Enteric Virus Surveillance System (NREVSS) shows HMPV to be most active during late winter and spring in temperate climates.
HMPV is most likely spread from an infected person to others through
- secretions from 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 distinct annual seasons. HMPV circulation begins in winter and lasts until or through spring. HMPV, RSV, and influenza can circulate simultaneously during the respiratory virus season.
Prevention and Treatment
Currently, there is no specific antiviral therapy to treat HMPV and no vaccine to prevent HMPV. Medical care is supportive. However, your patients can help prevent the spread of HMPV and other respiratory viruses by following these steps:
- Wash their hands often with soap and water for at least 20 seconds (see CDC’s Clean Hands Save Lives!).
- Avoid touching their eyes, nose, or mouth with unwashed hands.
- Avoid close contact with people who are sick.
Patients who have cold-like symptoms should
- cover their mouth and nose when coughing and sneezing
- wash their hands frequently and correctly (with soap and water for at least 20 seconds)
- avoid sharing their cups and eating utensils with others
- refrain from kissing others
- stay at home when they are sick
In addition, cleaning possible contaminated surfaces (such as doorknobs and shared toys) may potentially help stop the spread of HMPV.
In healthcare settings, healthcare providers should follow CDC’s 2007 Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings.
Since HMPV is a recently recognized respiratory virus, healthcare professionals may not routinely consider or test for HMPV. However, healthcare professionals should consider HMPV testing during winter and spring, especially when HMPV is commonly circulating.
Infection with HMPV can be confirmed usually by
- direct detection of viral genome by polymerase chain reaction assays, and
- direct detection of viral antigens in respiratory secretions using immunofluorescence or enzyme immunoassay.