A new cold virus is sending U.S. children to hospital with symptoms that resemble swine flu, doctors are reporting. At the Children’s Hospital of Philadelphia, hundreds of children had a rhinovirus (common cold virus), leading federal health investigators to wonder whether it’s a new strain, and whether it’s impacting other parts of the country, too. “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, which (unlike most U.S. hopsitals) can run a test to diagnose 10 different respiratory viruses, including influenza. While most rhinoviruses cause an illness that can resemble the flu, with more runny nose and less fever, this one was causing severe symptoms and even pneumonia. Some children had to be hospitalized and treated with a nebulizer, which delivers drugs into the lungs to keep oxygen in the blood. The U.S. Centers for Disease Control is investigating, and notes that, while swine flu is above epidemic levels, only 30 per cent of cases of influenza-like illness that are tested are confirmed as H1N1.