Human Metapneumovirus Sees Increase in Incidence Rates

According to the CDC, the human metapneumovirus (HMPV) can cause upper and lower respiratory disease in people of all ages, but young children, older adults, and people with weakened immune systems, and are among the most susceptible to it.

HMPV was first discovered in 2001, and is in the paramyxovirus family along with respiratory syncytial virus (RSV). Molecular diagnostic testing has increased identification and awareness of HMPV as an important cause of infection.

This is a seasonal virus that occurs mostly during the fall, winter, and early spring months, and typically causes respiratory infections that can present with cough, fever, nasal congestion, and shortness of breath. In more severe cases, it can develop into bronchiolitis or pneumonia.

The CDC reports the total number of human metapneumovirus (HMPV) tests performed every week, and the number of those tests that were positive.

CDC says reporting delays may be expected for some laboratories. “…data shown for the more recent weeks may be less complete than others. Each point on the trend graphs below displays the average number of HMPV tests that were performed by census region, and the average percent of those that were positive from three adjacent weeks: the specified week, and the weeks preceding and following it. This is also known as a centered 3-week moving average.”

In the most recent reporting week (2/18/23), across the United States, the antigen detection was 15% and the PCR detection was 10% positivity. These rates are the highest this season, and reflects anecdotal evidence that clinicians are seeing more cases of HMPV. There are 4 regions are the Northwest, South, Midwest, and West. Each region has seen increases and the trends have shown the incidence curve going upward.

The PCR Detection Positivity Rate was the following the week of 2/18:

• The Northeast: 14%
• The South: 10%
• The Midwest: 8%
• The West: 9%
  
  

In terms of treatment, there is no specific antiviral therapy to treat HMPV and no vaccine to prevent it.

The CDC recommends that individuals who have HMPV to take the following precautions to prevent spread of the virus:

• Cover up for coughs and sneezes
• Practice proper handwashing (scrub with soap for at least 20 seconds Avoid sharing cups and utensils
• Avoid kissing others
• Wipe down all possibly contaminated surfaces