About the Influenza Virus If You Get Sick... Flu Surveillance Flu Vaccine Information Flu Facts for Providers Other Flu Related Links
Clean - Wash your hands, Cover - Cover your cough and sneeze, Contain - COntain your germs; stay home if you are sick

2002 - 2003 Flu Activity Report

While influenza is not a reportable disease in Illinois, the Illinois Department of Public Health examines reports from many health care sites throughout the state. These sites include physician offices, emergency departments and nursing homes that report acute illness, and schools that report absenteeism rates. Accordingly, the Department monitors disease trends and influenza activities as they occur on a weekly basis.

Year Week Beginning Week Ending Reported Influenza Activity
2003 April 13 April 19 No Activity
2003 April 6 April 12 No Activity
2003 March 30 April 5 No Activity
2003 March 23 March 29 No Activity
2003 March 16 March 22 No Activity
2003 March 9 March 15 Sporadic Activity
2003 March 2 March 8 Sporadic Activity
2003 February 23 March 1 Sporadic Activity
2003 February 16 February 22 Sporadic Activity
2003 February 9 February 15 Regional Activity
2003 February 2 February 8 Regional Activity
2003 January 26 February 1 Regional Activity
2003 January 19 January 25 Sporadic Activity
2003 January 12 January 18 Sporadic Activity
2003 January 5 January 11 Sporadic Activity
2003 December 29 January 4 Sporadic Activity
2002 December 22 December 28 No Activity
2002 December 15 December 21 No Activity
2002 December 8 December 14 No Activity
2002 December 1 December 7 No Activity
2002 November 24 November 31 No Activity
2002 November 17 November 23 No Activity
2002 November 10 November 16 No Activity
2002 November 3 November 9 No Activity
2002 October 27 November 2 No Activity
2002 October 20 October 26 No Activity
2002 October 13 October 19 No Activity

No Activity No lab confirmed cases †
Sporadic Activity Isolated lab-confirmed cases OR Lab confirmed outbreak in one institution ‡
Local Activity Recent (within the past 3 weeks) lab evidence of influenza in region with increased ILI* OR Recent (within the past 3 weeks) lab evidence of influenza in region with the outbreaks; virus activity is no greater than sporadic in other regions**
Regional Activity Increased ILI* in >2 but less than half of the regions AND recent (within the past 3 weeks) lab confirmed influenza in the affected regions. OR Institutional outbreaks (ILI or lab confirmed) in >2 and less than half of the regions AND recent lab confirmed influenza in the affected regions**. A region is defined as the regions States use for public health purposes.
Widespread Activity Increased ILI* and/or institutional outbreaks (ILI* or lab confirmed) in at least half of the regions** AND recent (within the past 3 weeks) lab confirmed influenza in the state.

*ILI activity can be assessed using a variety of data sources including sentinel providers, school/workplace absenteeism, and other syndromic surveillance systems that monitor influenza-like illness.
Lab confirmed case=case confirmed by rapid diagnostic test, antigen detection, culture, or PCR. Care should be given when relying on results of point of care rapid diagnostic test kits during times when influenza is not circulating widely. The sensitivity and specificity of these tests vary and the predicative value positive may be low outside the time of peak influenza activity. Therefore, a state may wish to obtain laboratory confirmation of influenza by testing methods other than point of care rapid tests for reporting the first laboratory confirmed case of influenza of the season.
Institution includes nursing home, hospital, prison, school, etc.
** Region: population under surveillance in a defined geographical subdivision of a state. A region could be comprised of 1 or more counties and would be based on each state's specific circumstances. Depending on the size of the state, the number of regions could range from 2 to approximately 12. The definition of regions would be left to the state but existing state health districts could be used in many states. Allowing states to define regions would avoid somewhat arbitrary county lines and allow states to make divisions that make sense based on geographic population clusters. Focusing on regions larger than counties would also improve the likelihood that data needed for estimating activity would be available.

Learn about Who Needs A Flu Vaccine.

535 West Jefferson Street • Springfield, Illinois 62761 • Phone 217-782-4977 • Fax 217-782-3987 • TTY 800-547-0466
Questions or Comments

Seasonal Flu Home Page IDPH Home Page Influenza Home Page