DPH: Influenza Surveillance and Statistics

Influenza Surveillance and Statistics

 

 

In Connecticut, the Department of Public Health uses multiple systems to monitor circulating influenza viruses. During the influenza season, weekly flu updates are posted from October of the current year, through May of the following year. Annual summaries are also posted for comparison. The national flu picture may vary from what we are seeing on a state level.

 

This Week's Flu Update

 

 

Current Influenza Season Weekly Updates

 

To see how this year's influenza season has progressed, please click on the MMWR Week number that corresponds with the week's beginning and end date you are interested in seeing. Each report is progressive and includes data starting from the beginning of this flu season.



Year
                       

MMWR
Week
                        

Week
Beginning
                                      

Week
Ending 
                                       

Influenza Activity
Classification*
                                      
2016
January 24, 2016
January 30, 2016
Regional
20163January 17, 2016January 23, 2016Regional
20162January 10, 2016January 16, 2016Regional
20151January 3, 2016January 9, 2016Regional
201552December 27, 2015 January 2, 2016  Regional
201551December 20, 2015December 26, 2015Local
201550 December 13, 2015December 19, 2015Local
201549December 6, 2015December 12, 2015Local
201548November 29, 2015December 5, 2015Local
201547November 22, 2015November 28, 2015Sporadic
201546November 15, 2015November 21, 2015Sporadic
201545November 8, 2015November 14, 2015Sporadic
201544November 1, 2015November 7, 2015Sporadic
201543October 25, 2015October 31, 2015Sporadic
201542October 18, 2015October 24, 2015Sporadic
201541October 11, 2015October 17, 2015Sporadic
201540October 4, 2015October 10, 2015Sporadic



  

Connecticut Annual Summaries



National Statistics

 

Weekly national updates are available from the Centers for Disease Control and Prevention's (CDC) FluView website.



International Statistics

International influenza activity is available at the World Health Organization website.

 


Connecticut's Influenza Surveillance Systems

  • Hospital Emergency Department Syndromic Surveillance (HEDSS). This system receives daily electronic reports on emergency department visits from more than half of Connecticut's acute care hospitals. Data include a listing of total patient visits with information on their chief complaint, including fever/flu.
  • Sentinel Provider Surveillance. Reporting of influenza-like illness (ILI) is conducted through a statewide network of volunteer outpatient providers known as ILINet. The proportion of patients exhibiting ILI is reported to the DPH on a weekly basis. ILI is defined as a cough or sore throat in the absence of a known cause, and the presence of a fever greater than 100 degrees Fahrenheit.
  • Hospital Admissions Syndromic Surveillance (HASS). This system receives daily electronic reports from all 32 acute care hospitals in Connecticut. Information on unscheduled admissions, including those for pneumonia that may be associated with influenza infections, is submitted.
  • Influenza-associated Hospitalizations. In Connecticut, influenza-associated hospitalizations and deaths are reportable to the DPH. Data collected describe the more serious illnesses associated with influenza infections.
  • Laboratory Surveillance. Positive influenza tests are laboratory reportable findings in Connecticut. The DPH tracks these results to determine what types, subtypes, and strains are circulating.

Influenza Activity Classification Definitions*

 

No Activity No laboratory-confirmed cases AND no increase in the number of cases of ILI.
Sporadic Activity Small numbers of lab-confirmed cases OR lab confirmed outbreak in one institution, but NO increase in cases of ILI.
Local Activity Outbreaks of influenza or increases in ILI cases AND recent^ laboratory-confirmed influenza in a single region# of the state.
Regional Activity Outbreaks of influenza or increases in ILI cases AND recent laboratory-confirmed influenza in at least 2 but less than half of the regions of the state with recent laboratory evidence of influenza in those regions.
Widespread Activity Outbreaks of influenza OR increases in ILI cases AND recent laboratory-confirmed influenza in at least half the regions of the state with recent laboratory evidence of influenza in the state.

*Reporting of influenza-like illness (ILI) is conducted through a statewide network of volunteer outpatient providers known as ILINet.

^Recent is defined as within 2 weeks.

#In general, counties within Connecticut are identified as regions for general data collection and dissemination. The state is also broken down into 5 planning regions by the Division of Emergency Management and Homeland Security (DEMHS). These regions are used by the DPH for influenza surveillance in the event of a novel flu outbreak.





Content Last Modified on 2/4/2016 11:04:26 AM