Human metapneumovirus, more commonly referred to as hMPV, is a virus that affects the respiratory tract. It’s from the same family as the respiratory syncytial virus (RSV).
Since the discovery of hMPV, it is now considered the 2nd or 3rd leading cause of lower respiratory viral infections and viral pneumonia in children needing medical attention, Chang added.
“Like RSV and influenza, hMPV also has annual epidemics in the late winter and early spring, usually 1-2 months following the RSV and flu season,” said Dr. Michael Chang, a pediatric infectious diseases expert at UTHealth Houston and Children’s Memorial Hermann. “For any given respiratory viral season (October through April), hMPV usually accounts for 5 to 10% of symptomatic respiratory viral infections, though this will be higher during the peak of the hMPV season.”
Dele Ogunseitan University of California, Irvine – Program in Public Health Professor, Population Health and Disease Prevention, PhD, told Healthline that hMPV causes lower respiratory tract information and that only RSV is more common.
“Many viruses that infect humans to cause respiratory diseases similar to the common cold may surge in recent months because most parts of the world went through a hibernation (lock-down) for the past two years, and many of these viruses did not circulate in the population,” Ogunseitan said. “We did not acquire the types of natural immunity that might have staved off infection. When people started mingling and traveling recently, these infections surge.”
Common symptoms of hMPV include:
- Nasal congestion
- Sore throat
Other more severe symptoms include lower respiratory tract symptoms such as croup, bronchiolitis (like RSV), pneumonia, and asthma exacerbation.
It’s important to note that bronchiolitis is not the same as bronchitis in adults. Bronchiolitis and asthma exacerbations likely present with expiratory wheezing, possibly even in kids without a history of wheezing before, Chang explained. Bronchiolitis is more likely in pre-school-aged children and younger.
Lower respiratory tract disease may be severe enough to require hospitalization and even intensive care in rare cases. Also, hMPV is associated with ear infections.
“The vast majority of patients with acute hMPV infection are children and will have the most common upper respiratory symptoms; runny nose, cough, fever. Occasionally, you can see pink eye from hMPV,” Chang said.
As far as symptoms in adults, the symptoms of hMPV may look slightly different.
“Adults with hMPV infection may have viral pneumonia, worsening asthma, or chronic obstructive pulmonary disease (COPD) symptoms. Adults can get bronchitis,” said Chang. “Generally, hMPV infection looks a lot like RSV infection.”
Testing is necessary to differentiate between the two conditions.
“For most children and adults, you won’t be able to tell hMPV from a cold without testing,” Chang stated. “Also testing for hMPV isn’t that common in the outpatient setting, and many hospitals don’t test for hMPV for inpatients either. Testing is in the form of a nasal swab to look for the viral genetic material via PCR.”
It is not generally possible for patients to tell the difference between cold viruses and hMPV, but laboratory tests may be able to differentiate and identify the specific virus involved, Ogunseitan explained.
“The symptoms typically clear up with rest and similar over-the-counter treatments as for the common cold. Any patient with severe infection including difficulty breathing should seek medical care promptly,” said Ogunseitan.
Seeking professional medical care is important if someone thinks they are infected, and parents of infants should be particularly cautious. Common hygienic practices, including hand washing and mask-wearing should reduce the risk of infection, Ogunseitan noted.
There are no specific antiviral treatments for hMPV.
“For most patients, symptomatic care at home with hydration and fever reducers will work great,” said Chang. “For infants and children that require hospitalization, supplemental oxygen, hydration, and supportive care will be the primary treatments.”
“Children younger than age 2 at the greatest risk for hospitalization from hMPV. Also, children with underlying diseases such as history of prematurity, bronchopulmonary dysplasia, congenital heart disease, asthma, and compromised immune symptoms are at risk for more severe disease from hMPV,” Chang stated.
In adults, patients older than 65 with underlying chronic heart or lung disease, including asthma and COPD, or who are immunocompromised are at increased risk for severe illness, Chang added.
A new report issued by the CDC shows a spike in the number of human metapneumovirus (hMPV) cases.
The common symptoms of this virus include cough, runny nose and sore throat. Testing is necessary to tell the difference between hMPV and the common cold.
Although there are no specific treatments, symptomatic care at home with hydration and fever reducers can be beneficial.
Children younger than age 2 are most at risk of hospitalization due to hMPV.