Causes and Risk Factors of Human Metapneumovirus

Human metapneumovirus (hMPV) is one of many viruses that causes an upper respiratory infection with common cold symptoms. As with other viruses, human metapneumovirus is contagious. The virus spreads through respiratory droplets, such as by coughing or sneezing. 

This article explores how human metapneumovirus spreads, the risk factors for acquiring it, and who might be at higher risk for complications.

Common Causes 

The main way that human metapneumovirus spreads is through respiratory droplets. A person infected with metapneumovirus can transmit the virus if they cough or sneeze, for instance. 

You may also acquire the virus if you touch a surface that a person with hMPV touched or have close physical contact with them (such as by shaking hands).

Human metapneumovirus is in the same family (paramyxovirus) as respiratory syncytial virus (RSV). HPMV was discovered in 2001, but researchers believe it has been circulating for close to 70 years.

Risk Factors

Everyone is vulnerable to cold viruses, including the human metapneumovirus. However, hMPV is particularly common in young children and infants. Almost all children contract the virus by age 5. But immunity after infection is not strong, so it is possible to have reinfection by the virus throughout life.

Certain factors can increase your risk of getting human metapneumovirus, including environmental factors that can speed up transmission.

Environmental Risk Factors

As with other cold viruses, hMPV spreads through respiratory droplets. This can occur if someone coughs or sneezes. It can also happen if they touch their face, mouth, or nose and transmit the virus to surfaces. 

Transmission from person to person is more likely with:

• Frequently touched surfaces like doorknobs or light switches 
• Poor hygiene, since not washing your hands or disinfecting surfaces can lead to transmission of the virus
• Crowded environments like public transit, hospitals, and schools
  

According to the American Lung Association, hMPV is more likely to circulate during the winter and spring months.

Health Risk Factors

While hMPV is common, not everyone will experience symptoms, or their symptoms may be mild. A healthy immune system can often fight off infections like the common cold, preventing severe symptoms from developing. 

However, some people are more likely to contract cold viruses like hMPV and experience severe complications. These include:

• Infants
• Young children
• Older adults
  

These people are also more likely to develop lower respiratory symptoms and severe complications. The same is true of:

• People with weakened immune systems, including people with cancer, human immunodeficiency virus (HIV), people undergoing cancer treatment, and people after an organ transplant 
• Pregnant people
• People with asthma (a chronic condition of inflamed and constricted airways)
  

Summary

Human metapneumovirus is a contagious viral illness that causes symptoms like runny nose, coughing, and congestion.

Anyone can contract hMPV, but not everyone develops symptoms beyond mild cold symptoms. Rarely do people develop serious complications. Children, infants, older adults, and people with weakened immune systems are most likely to develop serious symptoms.

You’re also more likely to get hMPV if you practice poor hygiene, live or interact closely with someone who has the virus, or frequent crowded spaces where someone might transmit the virus.

A Word From Verywell 

Human metapneumovirus is just one of the viruses that can cause an upper respiratory infection. When you catch a cold, you won’t know what virus is causing your symptoms. But prevention strategies remain the same. Make sure to wash your hands frequently, avoid sharing cups and utensils, and cover your mouth and nose when coughing or sneezing. 

Avoiding viral illnesses is particularly important for immunocompromised people. Their immune system isn’t strong enough to fight off invaders like viruses. This leaves them vulnerable to complications like pneumonia. 

Protecting yourself from hMPV also helps protect those around you who are more vulnerable than you. If you don't have the virus, you can't spread it to others.