Monitoring & Surveillance

Flu Season ¹Weekly Surveillance, 2007 - 2008

  Click here to download the latest ² interactive update. Click here to download the latest printable (not interactive) update.

Click here for a comparative look at the magnitude of past flu seasons.

¹ The surveillance graphs visualize disease incidence over a specific weekly interval known as the MMWR week.  The MMWR (Morbidity and Mortality Weekly Report) week is the week of the epidemiologic year for which the National Notifiable Diseases Surveillance System (NNDSS) disease report is assigned by the reporting local or state health department for the purposes of MMWR disease incidence reporting and publishing.  MMWR week supports reporting of notifiable infectious disease incidence data at the national level.  Some states may assign MMWR week for data management or reporting purposes more so than for monitoring ‘true’ disease incidence. 

The first day of any MMWR  week is Sunday.  MMWR week numbering is sequential beginning with 1 and incrementing with each week to a maximum of 52 or 53.  MMWR week #1 of an MMWR year is the first week of the year that has at least four days in the calendar year.  For example, if January 1 occurs on a Sunday, Monday, Tuesday or Wednesday, the calendar week that includes January 1 would be MMWR week #1.  If January 1 occurs on a Thursday, Friday, or Saturday, the calendar week that includes January 1 would be the last MMWR week of the previous year (#52 or #53).  Because of this rule, December 29, 30, and 31 could potentially fall into MMWR week #1 of the following MMWR year.

² This document contains multimedia content which enables you to view more detailed data by mousing over sections of the graphs.