The level of swine flu activity in the United States appears to be declining, although officials are worried about another increase of cases during the Thanksgiving holiday when many people travel and families gather. The number of states reporting widespread activity of the H1N1 virus dropped to 43 from 46 in the past week, and activity fell in all 10 regions of the country, according to the federal Centers for Disease Control and Prevention. But flu cases are still rising in some states, including Maine and Hawaii, and it is too soon to know whether activity will surge again, said Anne Schuchat, director of the CDC"s Center for Immunization and Respiratory Diseases. "Influenza is unpredictable, and it is so early in the year to have this much disease. We don"t know if these declines will persist, what the slope will be, whether we"ll have a long decline or it will start to go up again," she said. The news came as scientists in Norway announced that they had detected a mutated form of the swine flu virus in two patients who died of the flu and in a third who was severely ill. It is the most recent report of mutations in the virus that is being watched closely for any change that could make it more dangerous. "Based on what we know so far, it seems that the mutated virus does not circulate in the population, but might be a result of spontaneous changes which have occurred in these three patients," the statement said. Schuchat said the mutation is no reason for alarm. "I don"t think it has the public health implications that we would wonder about," she said, noting that some patients have gotten severely ill, including developing pneumonia, after being infected with strains of the virus without the mutation.
