WASHINGTON - The United States was in the grip of a deadly influenza outbreak that has hit harder and earlier than in previous years, and has claimed the lives of at least 18 children. “It looks like the worst year we’ve had since 2003-2004,” said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases. Fauci said this year’s influenza strain, which has sickened thousands across the country, is particularly severe. “The type of flu is one that generally is more serious. It’s the H3N2 variety, which is historically more serious than we see with other types of virus,” he told AFP. The epidemic, which broke out in early December, has caused some 2,200 hospitalizations across the United States, federal health officials said.