U.S. influenza activity continues to decline

Influenza activity in the United States has continued to decline despite the Centers for Disease Control and Prevention reporting twice as many flu-related pediatric deaths this week in comparison with last.

The CDC reported that the percentage of deaths from pneumonia and flu remained above the epidemic level for the ninth week in a row, according to CIDRAP News.

The number of states that have reported widespread flu activity fell from 18 to 10, with most, except Nevada and Virginia, located in the northern tier.

The percentage of doctors visits related to flu-like illness fell to two percent, below the national baseline of 2.5 percent, for the first time since the first week of January.

The total number of pediatric deaths related to the flu this season rose to 89, with twelve new deaths reported this week by the CDC. Of the deaths reported this week, four were associated with the 2009 H1N1 virus, four with influenza B, one with H3N2 and three with unsubtyped influenza A viruses.

The percentage of respiratory samples that tested positive for influenza has fallen from 19 percent to 13.9 percent in the last week, CIDRAP News reports. The CDC did not note major changes in the circulating virus levels. Of the positive samples, 29 percent were influenza B and 71.2 were type A. H3N2 accounted for 35.6 of the type A isolates and 21.7 percent were 2009 H1N1. The other 42.7 percent were not subtyped.

The CDC said that the predominant virus has varied weekly, regionally and even within states in the same region, CIDRAP News reports.