Williamson County Influenza Surveillance

Transcription

1 Williamson County Influenza Surveillance Williamson County and Cities Health District Weekly Update as of (Provisional Data) Last Week s Influenza Activity: Moderate

2 Total Reports Confirmed Flu (Bars) Total Reports ILI (Line) Influenza-like Illness (ILI) and Flu by Week (End Date) School Holiday Week End Date (+) Rapid A (+) Rapid B (+) Rapid ND (+) Culture/PCR A (+) Culture/PCR B ILI The WCCHD flu surveillance system does not attempt to capture all cases of influenza or influenza-like illness. The number of reporters sending in ILI and flu reports may vary from week to week. These data should be used to look for trends over time rather than for estimating the total number of cases. Rapid ND: Flu type not differentiated

3 Relative ILI Activity by Residence Area of LSCC* Patients *LSCC: Lone Star Circle of Care Residence area of an LSCC patient is determined by patient-reported zip code only. Zip codes are grouped into four city areas (Georgetown, Leander/Cedar Park/Austin, Round Rock/Hutto and Taylor) and one area for remaining rural Williamson County.

4 Influenza-like Illness (ILI) Reporting to WCCHD Data on ILI is collected throughout the season from a variety of sources. On a weekly basis, school districts report to WCCHD absences due to ILI. Hospitals report numbers of patients seen with ILI and/or flu (rapid test by type: A, B, or not differentiated). Lone Star Circle of Care reports total counts of ILI seen in their clinics, and they provide additional data derived from their electronic medical record system aggregated by age, gender and zip code of residence. RediClinics and Texas MedClinic report total ILI seen to CDC s ILINet and their data is available to WCCHD one week later. In addition, hospital emergency departments report chief complaint data to a syndromic surveillance system. Occasionally, other health departments relay information on cases from Williamson County seen by providers in other jurisdictions. Information related to each of these data streams is reviewed and analyzed by WCCHD weekly for trends.

5 Number of Reporters by Type Influenza-like Illness (ILI) Reporters by Week (End Date) Week End Date Clinic Hospital School District Public Health Lab Report Influenza is not a reportable condition. As a consequence, the WCCHD influenza surveillance system does not attempt to capture all cases of influenza or influenza-like illness (ILI). The number of reporters sending in ILI reports varies from week to week.

6 Total Flu Reports %Flu of Total ILI Reported Hospital-Reported Rapid Flu Tests by Week (End Date) 4 4.% % % % % 2 2.% % % 8 8.% 4 4.%.% Week End Date Confirmed Flu A Confirmed Flu B Confirmed Flu, Not Typed %Flu of ILI

7 Total ILI Reported Influenza-like Illness (ILI) by Reporting Source Week End Date Clinic Hospital School district ER Syndromic

8 %ILI of Total LSCC Clinic Visits Clinic (LSCC*) Visits for ILI by Age Group 4.% *LSCC: Lone Star Circle of Care 36.% 32.% 28.% 24.% 2.% 16.% 12.% 8.% 4.%.% Week End Date Pediatric Adult Williamson County

9 %ILI in Total Clinic Visits Age-Adjusted ǂ LSCC * ILI Rate Compared to Texas Rate ǂǂ 2.% 18.% *LSCC: Lone Star Circle of Care 16.% 14.% 12.% 1.% 8.% 6.% 4.% 2.%.% Week End Date ILINet/Texas ILI Rate LSCC Non-Adjusted ILI Rate LSCC Age-Adjusted Estimated ILI Rate ǂ Population estimate source: 21 Census, yr estimate counts, U.S. Census Bureau, Population Division, Release Date June 216 ǂǂ Texas ILI rate source: U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet), accessed

10 Residence Area of LSCC* Patients *LSCC: Lone Star Circle of Care Residence area of an LSCC patient is determined by patient-reported zip code only. Zip codes are grouped into four city areas (Georgetown, Leander/Cedar Park/Austin, Round Rock/Hutto and Taylor) and one area for remaining rural Williamson County.

11 %ILI of Total LSCC Clinic Visits %ILI by Residence Area 4.% *LSCC: Lone Star Circle of Care 36.% 32.% 28.% 24.% 2.% 16.% 12.% 8.% 4.%.% Week End Date Taylor Georgetown Round Rock/Hutto Rural Williamson County Cedar Park/Leander/Austin Williamson County

12 Number Cases ILI Reported to WCCHD Current and Past Influenza-like Illness (ILI) H1N1 Pandemic Reporting Enhancements Sep Oct Nov Dec Jan Feb Mar Apr May

13 Number of Positive Specimens Percent Positive Influenza Positive Specimens from Texas INFLUENZA POSITIVE SPECIMENS FROM TEXAS Reported by WHO/NREVSS Collaborating Laboratories and Seasons 12 3% 1 25% 8 2% 6 15% 4 1% 2 5% % Week Total A(H1) Total A(H3N2) Total A(Subtyping not Performed) Total A(29 H1N1) Total A(Unable to Subtype) Total B Total %Positive Source: National Center for Immunization and Respiratory Diseases (NCIRD), Centers for Disease Control and Prevention, Atlanta, GA, accessed

14 #Deaths Annual Influenza-related Mortality in Williamson County Year -24 years of age years of age 65 years of age Data Source: Texas Department of State Health Services, Vital Statistics, accessed at Most current data available as of

15 Helpful Links to References Google Flu Trends: CDC Weekly Surveillance Reports: Overview of national flu surveillance: The National Respiratory and Enteric Virus Surveillance System (NREVSS) Influenza surveillance in Texas: Communicable Disease Epidemiology at WCCHD: Elise Huebner, MS, CPH, CIC,