The swine flu virus is spreading rapidly throughout California and Los Angeles, officials said. More than half of local health departments in the state are seeing active outbreaks, Mark Horton, MD, the state public health officer, said at a news conference.
More than 5% of patients going to doctor's offices have flu-like symptoms, which is much higher than the usual 2%, according to an estimate based on about 50 physicians across California who monitor flu activity for the state.