New Virus Commonly Strikes Children
Human Metapneumovirus May Be Major Cause of Respiratory Illnesses
Jan. 28, 2004 -- For many kids with respiratory infections, doctors are unable to pinpoint a specific cause. But a new study shows that a recently discovered virus may be responsible for up to one in five of these respiratory illnesses.
Researchers suggest that the virus, called the human metapneumovirus, appears to be one of the leading causes of respiratory infection in the first years of life and causes symptoms similar to those associated with the respiratory syncytial virus (RSV), such as difficulty breathing and wheezing.
Researchers say RSV and influenza are thought to be the most common causes of respiratory infections among infants and children, but there are a substantial number of cases in which no virus can be identified.
In 2001, researchers in the Netherlands identified a new virus found in adults and children with respiratory infections, but until now the rate of infection caused by human metapneumovirus in children was not known.
Human Metapneumovirus Common in Children
In the study, published in the Jan. 29 issue of The New England Journal of Medicine, researchers tested for human metapneumovirus in otherwise healthy infants and children who were treated for respiratory illness.
Of the 248 nasal samples tested, researchers found the human metapneumovirus in 49 of the samples.
Researchers say that means 20% of lower respiratory tract illnesses -- such as bronchitis or pneumonia -- were caused by the human metapneumovirus. In addition, they estimate that 12% of all lower respiratory tract illnesses may be due to this virus.
The study also showed that much like other viruses that cause respiratory illness, infections with the human metapneumorvirus are most common during the winter.
Symptoms of the New Virus
The most common symptoms of human metapneumovirus infection in children are similar to other respiratory infections -- cough, fever, irritability, and runny nose.
There is no known treatment for human metapneumovirus. Fortunately, infection is rarely deadly, although 1 in 50 kids infected with the virus required hospitalization in a previous study.
In an editorial that accompanies the study, Kenneth McIntosh, MD, of Harvard Medical School, and colleagues say the findings "indicate that the human metapneumovirus is, with a few differences, a kid brother or sister to the respiratory syncytial virus (RSV) that, particularly in young children, accounts for a very substantial proportion of cases previously relegated to the 'undiagnosed' category."
They say further research is now needed to better understand exactly what role the newly discovered virus plays in diseases found in adults and to develop ways to prevent the infection.