Explained: What Is Human Metapneumovirus? The Pathogen Whose Cases Saw A Recent Surge In The US

Human metapneumovirus: This spring, an increasing number of people infected with human metapneumovirus were being admitted to intensive care units (ICUs) in the United States.

Human metapneumovirus: The United States has recently seen a rise in the cases of human metapneumovirus, a pathogen that can cause upper and lower respiratory tract diseases. 

In the beginning of March, there was a 19.395 per cent increase in the antigen detection of human metapneumovirus, and a 10.368 per cent increase in the PCR (polymerase chain reaction) detection of the pathogen, according to data provided by the Centers for Disease Control and Prevention (CDC). 

The CDC says on its website that during the previous four years before the Covid-19 pandemic, the circulation of human metapneumovirus peaked between 6.2 per cent and 7.7 per cent in March and April, which means that the weekly percentage of positive cases never went beyond 7.7 per cent. In 2020 and 2021, the weekly percentage of positive cases of the virus remained low. 

This spring, an increasing number of people infected with human metapneumovirus were being admitted to intensive care units (ICUs) in the US, the country's media reported.

Here's everything you need to know about human metapneumovirus. 

Human metapneumovirus and its symptoms

Human metapneumovirus, which causes upper and lower respiratory tract diseases, especially in young children, older adults, and people with compromised immune systems, results in symptoms such as cough, nasal congestion, fever and shortness of breath. 

Other symptoms include wheezing, difficulty breathing, and hoarseness, among others, according to the Illinois Department of Public Health. 

However, if the infection becomes severe, one may experience symptoms such as bronchitis and pneumonia. In adults with asthma, conditions may be exacerbated following infection with the virus. It takes about three to six days for the symptoms to appear following infection with the virus. 

Children younger than one year of age, the elderly and people with weak immune systems are more likely to have serious respiratory illness from human metapneumovirus. 

It was discovered in the Netherlands in 2001, and belongs to the Pneumoviridae family, to which the respiratory syncytial virus belongs too. In early May this year, the US Food and Drug Administration approved the world's first respiratory syncytial virus vaccine.  

Temperate regions usually see the greatest activities of human metapneumovirus during late winter and spring. 

How human metapneumovirus is transmitted and diagnosed

Human metapneumovirus is transmitted from an infected person to others by touching objects that have the virus on them, and then touching the nose, mouth or eyes, through secretions from coughing and sneezing, or by touching or shaking hands with an infected person. 

Infection with human metapneumovirus can be diagnosed either through direct detection of viral genome by polymerase chain reaction assays, or through direct detection of viral antigens in respiratory secretions. 

How human metapneumovirus is prevented and treated

Human metapneumovirus infection can be prevented by protecting oneself from people who could be infected, or covering one's mouth and nose when near people who are coughing or sneezing. 

Also, basic hygiene such as washing hands after touching dirty objects must be maintained. The CDC recommends washing hands for at least 20 seconds. 

People with symptoms of human metapneumovirus must maintain the same precautions to ensure others do not get infected from them. Also, they must not share their objects, including utensils, with others.

Contaminated surfaces must be frequently cleaned to avoid the spread of the virus. 

Currently, there is no specific antiviral therapy to treat human metapneumovirus, or no vaccine to prevent infections with the virus, and the only treatment is supportive care. 

Patients are usually given antihistamines, fever reduction medications or breathing treatments.