BOSTON (Reuters) - A highly contagious respiratory virus is far more widespread among children than once thought and puts more of them in the hospital than influenza, U.S. researchers reported on Wednesday.
They projected that the respiratory syncytial virus, known as RSV, affects 2.1 million children under the age of 5 each year.
Over four years, from November through April, the virus was responsible for 20 percent of hospitalizations, 18 percent of visits to emergency rooms and 15 percent of office visits for respiratory infections in children under 5 in three U.S. counties, Dr. Caroline Breese Hall of the University of Rochester Medical Center in New York and colleagues found.
"This causes hospitalization in children three times as often as influenza," Hall said in a telephone interview.
She said the findings show that researchers should place more emphasis on finding a vaccine for RSV.
Until now, most of the concern around the virus had been for newborns, up to 1 year of age, and children with high-risk medical conditions.
Hall's team reported in the New England Journal of Medicine that only 3 percent of the RSV cases were correctly diagnosed, and that most of its victims were older than 1 year.
"These kiddies are not the young babies on which we've focused, but they are older and are quite severely ill. Seventy-three percent have had some kind of difficulty in breathing. That's significant," she said.
Most of the children who became ill had no previous health problems.
In many instances, because the illness was misdiagnosed, the children were treated with antibiotics, which are ineffective, Hall said.
Editing by Maggie Fox and Xavier Briand