Runny nose, fever, cough, even pneumonia -- the symptoms sound like swine flu but children hospitalized at one U.S. hospital in fact had a rhinovirus, better known as a common cold virus, doctors said on Tuesday.

Hundreds of children treated at Children's Hospital of Philadelphia had a rhinovirus, and federal health investigators are trying to find out if it was a new strain, and if this is going on elsewhere in the country.

"What began to happen in early September is we started seeing more children coming to our emergency room with significant respiratory illness," said Dr. Susan Coffin, medical director of infection control and prevention at the hospital.

Doctors and parents assumed it was the new pandemic H1N1 swine flu, which would be expected to re-emerge as schools began in September. But it was not, Coffin said in a telephone interview.

The hospital, unlike most hospitals in the United States, runs a test that can diagnose 10 different respiratory viruses, including influenza but also rhinoviruses, parainfluenza viruses and other germs that make kids sick.

"The data showed us it wasn't H1N1 but instead was this rhinovirus infection," Coffin said.

Usually rhinoviruses cause an annoying but benign illness that looks a lot like flu, but with more runny nose and usually less of a fever. This one was causing severe symptoms and even pneumonia.

"Some of these kids had really bad wheezing," Coffin said -- so bad they had to be hospitalized and treated with a nebulizer, which delivers drugs into the lungs to help keep oxygen in the blood.

... contd.