FIGURE WO-20 Total influenza viruses from sentinel surveillance by type and week reported to August 23, 2009, and the total percentage positive from the swabs received, New Zealand.
NOTE: All results of sentinel swabs are received by Environmental Science and Research (ESR). The line shows the proportion of those swabs that test positive for any type of influenza. A low proportion may be due to the swabs not successfully retrieving the virus, or that influenza-like-illness (ILI) presentations to sentinel general practioners (GPs) are due to other viruses.
SOURCE: Reprinted from Lopez and Huang (2009) with permission from the Institute of Environmental Science and Research Limited.