Influenza Surveillance in Georgia
Georgia is part of the Centers for Disease Control and Prevention (CDC) influenza surveillance system. There are nine components to influenza surveillance in Georgia.
Each year from October to mid-May, Georgia's Department of Public Health tracks influenza-like illness throughout the State and reported in the Georgia Weekly Influenza Report.
- The Georgia Department of Public Health monitors influenza (flu) activity year-round throughout the state with the help of volunteer sentinel healthcare providers. We monitor influenza activity by calculating the percentage of provider visits that are for "influenza-like illness" (fever >100° F AND cough and/or sore throat). When the percentage of provider visits for influenza-like illnesses begins to increase compared to background levels, we suspect that influenza is active in that area. Although influenza activity typically peaks during the winter months, influenza viruses circulate year-round and remain a threat to persons who are very young or old or who have chronic medical conditions. The emergence of a new influenza strain capable of causing a pandemic is also a possibility; year-round surveillance improves public health’s ability to rapidly identify new strains of the virus.
- In addition to weekly reporting, volunteer sentinel providers send throat swabs from patients for laboratory testing (virologic confirmation and subtyping) at the Georgia Public Health Laboratory. Data and isolates are shared with CDC and help determine which influenza strains will be included in next year's influenza vaccine.
The state public health laboratory and several participating hospital laboratories throughout Georgia report the total number of specimens tested and the number positive for influenza types A and B each week to CDC. For more information on NREVSS, please visit http://www.cdc.gov/surveillance/nrevss/.
Each week, the vital statistics offices in Atlanta and Savannah report to CDC the total number of death certificates filed and the number of those for which pneumonia or influenza was listed as the underlying or as a contributing cause of death. These data are available at http://wonder.cdc.gov/mmwr/mmwrmort.asp. Nationally, the percentage of all deaths due to pneumonia and influenza are compared with a baseline and epidemic threshold value calculated for each week.
State health departments report the estimated level of influenza activity in their states each week. States report influenza activity as no activity, sporadic, local, regional, or widespread. These levels are defined as follows:
- No Activity: No laboratory-confirmed cases of influenza and no reported increase in the number of cases of ILI.
- Sporadic: Small numbers of laboratory-confirmed influenza cases or a single influenza outbreak has been reported, but there is no increase in cases of ILI.
- Local: Outbreaks of influenza or increases in ILI cases and recent laboratory-confirmed influenza in a single region of the state.
- Regional: Outbreaks of influenza or increases in ILI and recent laboratory confirmed influenza in at least 2 but fewer than half the regions of the state.
- Widespread: Outbreaks of influenza or increases in ILI cases and recent laboratory-confirmed influenza in at least half the regions of the state.
- Laboratory-confirmed influenza-associated deaths in children less than 18 years old are reported to CDC.
- Influenza-associated Mortality
- Laboratory-confirmed influenza-associated deaths in all Georgia residents (all ages) are reported to the State of Georgia.
- Nine EIP sites throughout the country, including an EIP site in eight counties of Metropolitan Atlanta, collect reports of laboratory-confirmed, influenza-related hospitalizations in adults and children.
- Novel strains of influenza A are notifiable and reported through the Georgia Public Health Laboratory to CDC.
Syndromic surveillance monitors Emergency Department patient chief complaint data. Influenza-like illness is captured in the “ILI” syndrome, a combination of patient complaints of fever and other complaints common to influenza-like illness. Information is collected daily using a secure, automated, electronic file transfer to the Division of Public Health and analyzed for trends by public health epidemiologists at the local and state level.