Number* and Percentage of Respiratory Specimens Testing Positive for Influenza, by Type, Subtype, Surveillance Week, and Year — World Health Organization and National Respiratory and Enteric Virus Surveillance System Collaborating Laboratories, United States, 2013–14 Influenza Season†

Notes: * N = 53,470.
† Data reported as of May 30, 2014.
Alternate Text: The figure above shows the number and percentage of respiratory specimens testing positive for influenza reported by type, subtype, surveillance week, and year in the United States during the 2013-14 influenza season. During September 29, 2013-May 17, 2014, World Health Organization and National Respiratory and Enteric Virus Surveillance System collaborating laboratories in the United States tested 308,741 specimens for influenza viruses; 53,470 (17.3%) were positive.

Data Source: Centers for Disease Control and Prevention

Source – Centers for Disease Control and Prevention: Influenza Activity — United States, 2013–14 Season and Composition of the 2014–15 Influenza Vaccines