Flu season data

Week ending November 28, 2009

Flu activity

Widespread flu activity

Regional flu activity

Localized flu activity

Sporadic flu activity

No flu activity

No report available

The flu activity indicator is provided by the US Centers for Disease Control, and indicates how widespread -- not how severe -- flu (both seasonal and H1N1) is in a given area. CDC monitors the flu season closely, and collects data from multiple sources:

  • Public health laboratories in all fifty states
  • ILINet, a nationwide network of medical facilities reporting on influenza-like illness (ILI)
  • Deaths reported to vital statistics offices in 122 cities around the country
  • The Emerging Infections Program, monitoring flu-related hospitalization in 12 major metropolitan areas
  • Reports from epidemiologists in each state

Source: CDC flu surveillance.

Flu mortality

All deaths in Kansas are reported to KDHE, which provides weekly information on the total number of deaths of all types, as well as deaths related to flu and pneumonia. KDHE also publishes news releases tracking deaths related to H1N1.

Deaths reported in Kansas, week ending 11/28/2009
Deaths (all causes) 299
Flu/pneumonia deaths (all types) 22
H1N1 deaths 0
Cumulative flu-related deaths (by age) in Kansas, 09/26/2009-11/28/2009
Under 5 0
5-18 0
19-24 0
25-49 16
50-64 34
65+ 260
Unknown 1
Total (all ages) 311

Source: KDHE epidemiology reports and news releases.

Self-reported influenza-like illness

Kansas participates in the Behavioral Risk Factor Surveillance System (BRFSS), a nationwide health survey coordinated by the Centers for Disease Control. The BRFSS questionnaire gathers information on general health, behaviors (such as smoking) which constitute health risks, use of preventive care and certain types of chronic diseases and injuries.

In September 2009, the BRFSS questionnaire was revised to include flu-related questions. Flu-related results from the revised BRFSS questionnaire are published by the Kansas Department of Health and Environment (KDHE) as part of its weekly reports on flu epidemiology in Kansas.

Although the information gathered through BRFSS is useful as a monitoring tool, a few important points must be stressed:

  • BRFSS data is self-reported: the information comes from people describing their own health and their families' health, not from doctors or other medical professionals.
  • The BRFSS questions gather data on influenza-like illness (ILI). Because this is not tied to any medical diagnosis, reports of ILI do not necessarily correspond to actual cases of flu.
  • Due to the nature of the survey, BRFSS data can lag somewhat behind other indicators. Each report of BRFSS data covers questionnaire responses for a two-week period.

Self-reported influenza-like illness in Kansas, 11/01/2009-11/15/2009

Self-reported influenza-like illness in Kansas, 11/01/2009-11/15/2009
Adults reporting ILI within previous 2 weeks 3.4%
Adults reporting ILI within previous 4 weeks 9.1%
Children reporting ILI within previous 4 weeks 38.2%
Housholds reporting ILI within previous 4 weeks 26.8%

Source: BRFSS (via KDHE epidemiology reports).

School absences

In addition to direct medical data such as hospitalization and mortality rates, KDHE tracks and publishes absence rates for schools in Kansas (gathered through local health departments). Weekly reports give the percentage of schools in each county which had 10% or more of students absent in that week.

Percentage of Douglas County schools reporting 10% or more of students absent, week ending 11/28/2009

Percentage of Douglas County schools reporting 10% or more of students absent, week ending 11/28/2009
Elementary schools 59%
Middle schools 29%
High schools 29%

Source: KDHE epidemiology reports.