Human Metapnuemovirus (hMPV)
Last Updated 11/02/2020
Author:Christian Sandrock, MD, FCCP
About Human Metapnuemovirus (hMPV)
Human metapneumovirus (hMPV) is an upper–respiratory tract virus. Your upper respiratory tract includes your nose, mouth, and throat. hMPV causes a basic infection, such as a cold. It typically occurs in the winter and early spring, with the flu season. The virus was first discovered in 2001.
- hMPV causes infections in people of all ages but is most common in children, especially those under 5 years of age.
- Symptoms include runny nose, blocked nose, cough, sore throat, headache, and fever. Few people may have shortness of breath. These symptoms go away on their own after a few days without treatment.
- A small number of people are at risk for a more severe pneumonia. People at particular risk include those who are over 75 years of age, those who take steroids, and those who take medication for cancer or after organ transplant.
hMPV is a virus that enters the body through contact with someone who is infected. It can enter through your mouth, eyes, or nose. It has been a leading cause of colds in children since its discovery in 2001. Studies have shown that most children have been infected with hMPV by 5 years of age. A smaller number of children (5% to 16%) will develop a lower–respiratory tract infection, such as pneumonia. Infants, specifically those in the first 5 months of life, seem particularly vulnerable.
This virus affects adults, as well. It usually affects adults who have been infected as a child. hMPV is a major factor for breathing illnesses in adults older than 65 years of age. It causes illness in up to 10% of people tested.
How hMPV affects your body
When hMPV enters your body, it infects the cells in your respiratory tract, including your mouth, nose, and throat. The infection of these cells causes your body’s immune system to respond. This response causes the symptoms of a cold, such as pain, low-grade fever, cough, runny nose, headache, and sore throat. In some people, the disease can spread to the main airways, or bronchi. This spread can lead to increased cough and wheezing. Children under the age of 1 year can experience decreased fever and weight loss.
In general, hMPV is not serious. Most people have few symptoms. Symptoms they do have get better on their own without treatment, usually within a few days.
People with asthma may have asthma flare-ups after infection. Such flare-ups are common with respiratory viruses.
Older adults and those whose immune systems are weakened are at higher risk for developing pneumonia that can be severe. However, hMPV appears less serious than other respiratory infections, including adenovirus and influenza.
One study showed that only 2.8% of hospitalized patients had pneumonia caused by hMPV.
Symptoms of hMPV
People with hMPV typically have no symptoms or mild symptoms similar to a cold. These symptoms include:
- Runny nose;
- Sore throat; and
Young children, older adults, and those with a weakened immune system may develop a more severe illness with hMPV. Symptoms of more serious illness include:
- Difficulty breathing;
- Asthma flare-ups; and
- Poor feeding (children under 1 year of age).
For those at increased risk for severe illness, more severe symptoms may include:
- A high fever;
- Shortness of breath;
- Inability to walk because of shortness of breath; and
Cough may become severe. It may also occur with severe wheezing. The cough may not get better with inhaler use.
Contact your health care provider if you have these symptoms.
What causes hMPV
The cause of hMPV is a virus. The virus is spread when a person comes into contact with an infected person. You are not more likely to get infection if you have a history of asthma, chronic obstructive pulmonary disease (COPD), emphysema, or any other lung disease. Likewise, a weak immune system, such as what happens when you have cancer or have had an organ transplant, does not increase your risk of getting an infection. However, once you’re infected, you may have a higher risk of severe symptoms and a more severe illness.
What are risk factors for hMPV?
The likelihood of getting an infection from the hMPV virus is the same regardless of other diseases such as asthma, COPD, cancer, or organ transplant. Smoking doesn’t seem to increase your likelihood of getting an infection, although it will make it harder to breathe if you have hMPV.
You’re at risk of developing more severe disease, including pneumonia, and wheezing if:
- You have asthma and use inhaled or oral steroids;
- Are a child under 1 year of age;
- Are an adult over 65 years of age;
- Have had an organ transplant;
- Have been on long-term steroids; or
- Have COPD.
There is no connected risk with other lung diseases, including pulmonary fibrosis or bronchiectasis. However, despite a lack of evidence, many health care providers feel that you have increased risk if you have these lung conditions.
As with influenza and respiratory syncytial virus (RSV), an hMPV infection can increase the risk for bacterial pneumonia.
Treatment works to relieve your symptoms.
Recent advances in medicine have helped providers recognize this illness. As a result, unnecessary treatments with antibiotic and antiviral medications has been reduced.
In addition, hMPV has been recognized as an issue in long-term care facilities, and outbreaks have been reported in schools. This finding shows the importance of early diagnosis to help prevent outbreaks of the virus.
Most health care providers will diagnose you with a cold based on your symptoms and the time of year. With this diagnosis, your health care team won’t try to find out which virus caused your symptoms because knowing won’t change the treatment you receive.
In some cases, particularly at the height of the flu season, your provider may test you for influenza. In this case, your testing will involve a nasal swab. Your health care provider inserts a long swab into the back of your nose for a sample. In some cases, the provider will spray some saline in your nose, and then collect the sample.
In severe cases, which are rare, your provider may order a bronchoscopy. During bronchoscopy, a small, flexible camera, or bronchoscope, is inserted into your mouth, down your windpipe (or trachea), and into your lung to remove a sample of fluid. This procedure is reserved for severe cases. The goal of this test is to detect influenza. This result helps guide your treatment.
Most people with a cold don’t need to see their provider.
However, call your health care provider if you develop:
- Shortness of breath;
- Severe cough;
- Inability to feed or care for yourself; and
- Symptoms that last for 14 days or longer.
There is no direct treatment for hMPV. Instead, your provider can help manage your symptoms. Your health care provider may suggest using medication such as acetaminophen (Tylenol) or ibuprofen (Advil, Motrin) to control pain and fever. He or she may also suggest decongestants, such as pseudoephedrine.
If you have wheezing or cough, your provider may recommend an inhaler. Finally, patients with more severe wheezing may need medications for asthma. This may include higher doses of an inhaled corticosteroid or oral prednisone.
Living with these symptoms for a long time is unlikely. If your symptoms last longer than 2 weeks, contact your health care provider. Otherwise, infection from hMPV will get better within days without lasting symptoms.
Infection with hMPV typically causes symptoms of the common cold that last roughly 2-5 days. By day 2 of infection, most people notice improvement. Many will feel completely fine by day 5. In those with asthma or other lung disease, symptoms may last a few days longer. However, symptoms rarely last more than 10 days.
Contact your health care provider if your symptoms last more than 14 days.
Protecting yourself from infection such as hMPV, influenza, and other contagious diseases is important, especially if you have a chronic lung disease such as COPD, asthma, or pulmonary fibrosis. Talk to your health care provider about how you can prevent illness. In addition, stay up to date on vaccinations and preventive health care appointments, such as a yearly physical examination.
The American Lung Association recommends that patients and caregivers join its Living with Lung Disease support community to connect with others facing this disease. You can also call the American Lung Association’s Lung Helpline at 1-800-LUNGUSA. Here, you can talk to a trained lung professional who can help answer your questions and connect you with additional support. Because these types of infections are short-term illnesses, long-term support is usually not available.
Questions to ask your health care provider
Many upper–respiratory tract infections don’t prompt specific questions to health care providers. Yet, some general questions for illness prevention are relevant to everyone. They may especially help those with active lung disease, cancer, or transplant issues.
- Am I at increased risk for getting a lung infection?
- If I get a lung infection, am I at increased risk for developing a severe pneumonia?
- Are there any lung infections that I should be concerned about, given my health?
- Am I at risk of having a worse or longer cold than the average person?
- What steps can I take to protect myself from getting a cold?
- How long should I wait after getting a cold before I come in and see you?