Pandemic H1N1 influenza activity declined slightly last week, with only 43 states reporting widespread activity, compared with 46 states the week before, officials at the Centers for Disease Control and Prevention said this morning.
Even though levels have declined, however, they are still "higher than peak activity in many years," said Dr. Anne Schuchat, director of the CDC's National Center for Immunization and Respiratory Diseases.
Officials fear, moreover, that flu activity will pick up as people travel around the country for Thanksgiving and Christmas. Unfortunately, she said, there are little data from seasonal flu on which to base predictions because such data are usually not prevalent so early in the year. Respiratory disease in general, however, does tend to increase early in the year after travel for the Christmas holidays. "We don't really know what is going to happen," she said.
There were an additional 21 laboratory-confirmed pediatric deaths last week, bringing the total for the year to 171 -- compared with 40 to 50 in a normal flu season. Fifteen of the deaths were confirmed to be caused by swine flu and the other six were confirmed to be caused by influenza A and are assumed to be swine flu. Overall, about two-thirds of the children who have died suffered from underlying conditions, such as asthma, cerebral palsy and muscular dystrophy.
As for the swine flu vaccine, "we are not where we want to be, but it is quickly being ordered and shipped," Schuchat said. As of this morning, 54.1 million doses have become available, 11 million more than were available last Friday, she said. About half of the doses shipped so far have been given to children, she said, and "the vast majority have gone to people who self-identified as being in a priority group." She said CDC will report data next week about potentially adverse events, "but so far we haven't seen any signals of unusual occurrences with swine flu vaccine or seasonal vaccine that would prompt us to feel urgent interventions are needed."
Schuchat also said that the agency is closely monitoring reports of an unusual strain of the swine flu virus that has been observed in some patients in Norway. The unusual strain has been seen sporadically in locations around the world, including the United States, she said, but so far there is no evidence that the mutation involved will make the virus more lethal or increase its resistance to the antiviral drug Tamiflu.
-- Thomas H. Maugh II