CDC reports decrease in flu activity

ATLANTA Although 43 states have reported widespread influenza activity for the week ended Nov. 14, numbers appear to be dropping, the Centers for Disease Control and Prevention noted Friday.

In its weekly situational update, the CDC reported that the number of states reporting widespread activity of the H1N1 virus dropped to 43 from 46 in the past week. Additionally, influenza-like illnesses nationally decreased again to 5.5%. This is the third consecutive week of national decreases after four consecutive weeks of sharp increases.

On a regional level, the percentage of outpatient visits for influenza-like illnesses ranged from 2.6% to 7.9% during week 45, and decreased in all 10 surveillance regions, compared with the previous week. All 10 regions, however, reported a proportion of outpatient visits for influenza-like illnesses above their region-specific baseline levels (2.3%).

"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," said Anne Schuchat, director of the CDC's Center for Immunization and Respiratory Diseases.

Meanwhile, there have been reports of cases that feature a mutated version of the virus, which apparently is resistant to antiviral Tamiflu, making the disease much more severe. Schuchat, however, 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.