MONDAY, June 2, 2003 (HealthDayNews) -- Infectious disease researchers have isolated a new respiratory virus in children.
But unlike the other respiratory virus making news -- SARS, or severe acute respiratory syndrome -- this virus appears to have been around for years.
Dubbed human metapneumovirus (hMPV), the virus was first discovered two years ago in the Netherlands. Since then, it has been found in Australia, Canada, the United Kingdom and now, the United States.
In a study appearing in the June issue of Pediatrics, Yale University researchers report finding hMPV in 6.4 percent of children tested.
"We don't know the cause of respiratory infections in about one-third of the cases," explains Dr. Jeffrey Kahn, an assistant professor of pediatrics, epidemiology and public health at Yale. "It appears that this virus causes a small, but significant, portion of those diseases."
Kahn says after originally isolating the pathogen, the researchers in the Netherlands went back and tested specimens from decades ago and found the virus was present back then.
For this study, Kahn and his colleagues collected respiratory samples from 296 children who were being treated for a respiratory illness. The children were under 5 years old. All of the youngsters tested negative for known causes of respiratory viruses, such as influenza and respiratory syncytial virus (RSV).
The researchers found hMPV in 19 of the children. Common symptoms of the disease were cough, fever and wheezing. None of the children died from the disease, Kahn says.
In a similar study, reported in the June issue of Emerging Infectious Diseases, Hong Kong researchers reported similar findings. Of 587 studied, they found 5.5 percent tested positive for hMPV.
Kahn says this disease can currently only be treated with supportive care, because there is no specific treatment or vaccine for it. Isolating the pathogen is the first step necessary for developing a commercially available test for the disease or for a vaccine, but Kahn says any vaccine is years away.
"We are just beginning to learn how hMPV is spread through the community and the biology of this virus," he says. "RSV was discovered in the 1950s, and the therapy hasn't changed since then."
"This study really suggests that this virus causes a significant percentage of the respiratory tract disease that we see," says Dr. Bishara Freij, a pediatric infectious disease specialist at William Beaumont Hospital in Royal Oak, Mich.
But, he adds, this study is only the first step. Now, he says researchers need to look at more children who have had this disease and figure out the symptoms and how it is transmitted, as well as if there is one group that is more susceptible than others.
Freij says it looks as if hMPV is transmitted in much the same way as RSV is, through respiratory secretions passed by direct transmission: for example, if a child sneezes into his hand and then touches another child who puts his hand in his mouth.
The best defense against viruses transmitted this way is frequent and thorough hand washing, though Freij acknowledges this isn't always easy with kids younger than 5.
More information
To learn more about common respiratory viruses, go to the National Jewish Medical and Research Center or the Medical College of Wisconsin.
