By Serena Gordon
WEDNESDAY, Feb. 4 (HealthDay News) -- It's called respiratory syncytial virus (RSV), a childhood infection that's responsible for one of every 13 visits to a pediatrician, and one of every 38 emergency room trips, a new study found.
What's more, the virus is to blame for inpatient hospital stays for one out of every 334 children. And, it's not just kids with underlying lung disease or immune system deficiencies -- the virus strikes healthy children, too.
"Although we've known for a long time that RSV is highly contagious and that RSV is the most important cause of lower respiratory tract infections in young children, this study gives us an idea of how common RSV infections are in the various age groups," said the study's lead author, Dr. Caroline Hall, a professor of pediatrics and medicine at the University of Rochester School of Medicine and Dentistry in New York.
Hall said that the incidence of RSV, particularly in children past infancy, was higher than the researchers had suspected.
"This study destroys some old paradigms," said Dr. Andrew Nowalk, an infectious disease specialist at Children's Hospital of Pittsburgh. "They [the study authors] found RSV to have a dramatic burden, even up to age 5. We've tended to assume that if you get past 1 year that RSV won't cause you many problems, but this study found that some older children were still being hospitalized."
RSV is a virus that causes cold-like symptoms, such as coughing, sneezing, runny nose, fever, a decreased appetite, and possibly wheezing. Nearly every child in America will have had RSV by the time they reach their second birthday, according to the U.S. Centers for Disease Control and Prevention. And, in most children, the disease will be mild, so it's often indistinguishable from other winter-time illnesses, according to Hall.
The virus is transmitted through sneezing or coughing, though Hall said you'd have to be very close to someone to catch RSV directly. But, the virus can live on surfaces, like countertops, desks, phones, computer keyboards, and if you touch these items and then rub your eyes, or touch your nose or mouth, you may become infected.
The new study, published in the Feb. 5 issue of the New England Journal of Medicine, included more than 5,000 children from three metropolitan areas who were hospitalized or seen as an outpatient in either an emergency department or pediatrician's office. At two sites -- Rochester, N.Y. and Nashville, Tenn. -- data was collected from 2000 through 2004. The other site -- Cincinnati -- provided data for the 2003-2004 RSV season.
From that large sample of children, 919 tested positive for RSV infections. RSV was responsible for 20 percent of hospitalizations, 18 percent of emergency department visits, and 15 percent of pediatric office visits for acute respiratory infections from November through April, according to the study.
Hospitalizations for RSV infection occurred more frequently than did those for influenza, Hall said.
"We tend to think of influenza as a very serious player, but when you compare this to influenza, RSV is much higher. This study suggests there should be a little more urgency for finding RSV vaccines," Nowalk said.
The researchers also tried to pinpoint risk factors for RSV, but only found that being born prematurely or a young age were independent risk factors. Being in day care, having other children at home, having been breast-fed and even living in a home with a smoker didn't seem to significantly raise the risk of RSV.
"We could not show other specific risk factors, probably because RSV is ubiquitous. And, it's just so highly contagious. Between 20 and 40 percent of parents will also get RSV if a child gets it," Hall said.
Nowalk added, "This paper suggests that it's going to be hard to prevent exposure to RSV."
Both experts recommended frequent and thorough hand washing, and Hall said to disinfect common household surfaces more often and try to avoid being around anyone with RSV.
Hall has consulted for MedImmune, maker of Synagis, which is used to prevent RSV in infants and young children at risk for infection, according to a University of Rochester Medical Center news release.