This memo (Influenza Update for NC Providers 1_5_2015) is intended to provide clinicians with updated epidemiologic information regarding the 2014–15 influenza season and to reinforce important prevention and control measures for the remainder of the season.

Influenza activity has been widespread in North Carolina since late November. So far, the predominant virus circulating in North Carolina and nationally has been the influenza A (H3N2) virus. H3N2-predominant seasons have been associated with more severe illness and mortality than H1N1- or B-predominant seasons, especially among older people and young children. Approximately two-thirds of H3N2 viruses characterized by CDC so far this season have not been well matched to the vaccine virus component, meaning that vaccine effectiveness against these viruses may be reduced. In this context, the use of influenza antiviral drugs as a second line of defense against the flu becomes even more important, especially for persons at high risk for complication and those with severe or progressive illness.

Additional guidance and weekly surveillance updates are available at www.flu.nc.gov.