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This article provides information on the Influenza Surveillance program in Texas, including data collection, reports, and analysis of flu activity. Learn about the different types of surveillance networks and how Texas contributes to national flu surveillance efforts.
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Texas Influenza Surveillance Lesley Bullion Influenza Surveillance Coordinator Infectious Disease Control Unit
Flu Surveillance Basics • Flu is not a notifiable condition* • Participation in surveillance is voluntary • “Official” flu season is approximately October to May (MMWR week 40 to MMWR week 20)
Texas Flu Surveillance • U.S. Outpatient Influenza-Like Illness Surveillance Network (ILINet) • Influenza-like illness (ILI) data • Culture Surveillance ‘Network’ • Specimens from clinics, hospitals, public health labs, health departments • Limited specimens from some ILINet providers • Research and Hospital Laboratories • Flu test results from NREVSS, WHO, TCH, S&W, USAFSAM • Regional Flu Surveillance Coordinator Reports • ILI, school closures, institutional outbreaks, laboratory results, rapid flu test results, pediatric flu deaths
U.S. Outpatient Influenza-Like Illness Surveillance Network (ILINet)
ILINet Basics • Voluntary nationwide network of healthcare providers sponsored by the Centers for Disease Control and Prevention (CDC) • Recruited by each state health department • Weekly reports of influenza-like illness (fever ≥100°F AND cough and/or sore throat in the absence of a known cause other than influenza) • Some Texas providers also submit specimens to DSHS
U.S. Outpatient Influenza-Like Illness Surveillance Network (ILINet), Texas Participants (N=143), 2008-09 As of 7/13/09
2008-09 Influenza Surveillance Specimens Submitted to DSHS Austin Lab (N=1,419*) *through April 15, 2009
Weekly Reports by Individual Labs • Texas Children’s Hospital: +cultures • Scott & White Hospital Laboratory: +tests (culture, PCR, antigen) by patient county • USAFSAM: +cultures/PCR by base • LRN laboratories: +PCR
NREVSS Laboratory Data NREVSS Flu Reporters in 2008-09 season: Arlington Memorial Hospital Children’s Hospital of Austin Children’s Medical Center of Dallas Cook Children’s Medical Center Covenant Medical Center Driscoll Children’s Hospital Hunt Memorial Hospital District Medical Center of Plano Medical City Dallas Hospital Methodist Children's Hospital Methodist Hospital Mother Frances Hospital Santa Rosa Health Care Scott & White Memorial Hospital South Texas Regional Medical Center Tarrant County Public Health Texas Children’s Hospital Texas Department of State Health Services Tomball Regional Hospital University Hospital/South Texas Medical Center University of Texas Medical Branch – Children’s Hospital University Medical Center
Flu Activity Levels • No Activity: • Low clinical activity and no lab confirmation • Sporadic: • ILI activity not increased • Isolated lab confirmed cases OR an institutional outbreak in a single institution • Local: • Increase in ILI plus recent lab confirmation inONE region of the state OR • Recent lab confirmation AND two or more ILI or lab confirmed outbreaks in ONE region • Regional: • Increased ILI OR institutional outbreaks in ≥2 but less than half of the regions • AND recent lab confirmation in affected regions • Widespread: • Increased ILI OR institutional outbreaks in at least half of the regions • AND recent lab confirmed influenza in affected regions
Texas Weekly Flu Report Flu activity level Regional reports Lab data Outbreaks SPSN ILI data Link to national report
How does Texas surveillance contribute to national surveillance?
National Flu Surveillance • Centers for Disease Control (CDC) components of influenza surveillance in the U.S. • Viral Laboratory Surveillance • Outpatient Illness Data • Mortality Surveillance • Hospitalization Surveillance • State and Territorial Epidemiologists Reports
2008–2009 Influenza Season in Texas (through April 15, 2009)
Texas Flu Summary, 2008–09 • First isolate of the season (DSHS Lab) • Flu A/unable to subtype! • Specimen collected October 15, 2008 • Bell County • Swine influenza A (H1N1) • Flu B • Specimen collected October 21, 2008 • B/Malaysia/2506/2004-like (Victoria lineage) • Webb County • Predominant type/subtype: A (H1N1)
Texas Flu Summary, 2008-09 • Early appearance of influenza B and A (H1N1) • Influenza A (H3N2) absent until week 52 • Seasonal peak: early February • 221 specimens collected, 147 (67%) positive for flu during week 5 (week ending February 7, 2009) • ILINet peak: 7.06% in week 6 • NREVSS-Texas peak: 28.1% in week 5 • “Widespread” designation for 7 weeks • Late, small flu B wave (week 8) • Mild compared to 2007-08
Influenza Types and Subtypes Identified in Positive Specimens, DSHS Austin Laboratory, 2008-2009 Season
Influenza-Associated Pediatric Mortality • Reportable beginning in 2007 in Texas • Laboratory-confirmed influenza death in a person under 18 years of age • 11 deaths (through week 15) • Age range: 7 months to 17 years • 4 Flu A, 7 Flu B • Known MRSA or MSSA co-infection: 2/11 (18%) • Significant underlying medical condition: 8/11 (73%) • Not vaccinated for flu: 4/6 (67%)
Review of 2008–09 Vaccine Components (Northern Hemisphere) • All 3 were new components! • A/Brisbane/59/2007-like (H1N1) • A/Brisbane/10/2007-like (H3N2) • B/Florida/4/2006-like (B/Yamagata lineage)
Antigenic Characterization Testing • Performed on limited Texas isolates at CDC laboratory • 20 A/H1 (seasonal) isolates: 100% match to vaccine strain • 8 A/H3 isolates: 100% match • 23 influenza B isolates: • 30% match to vaccine strain (Yamagata lineage) • 70% Victoria lineage
Antiviral Resistance Testing • Performed on limited Texas isolates at CDC laboratory • 1 swine influenza A/H1 tested (October 2008) • Sensitive to oseltamivir, zanamivir, adamantanes • 22 seasonal influenza A/H1’s tested • 100% resistant to oseltamivir (sensitive to zanamivir and adamantanes) • 7 influenza A/H3’s tested • 100% resistant to adamantanes (sensitive to oseltamivir and zanamivir) • 22 influenza B’s tested • 100% sensitive to oseltamivir and zanamivir
2009-10 Vaccine Composition (Northern Hemisphere) • Only the B strain will be changed: • A/Brisbane/59/2007-like (H1N1) • A/Brisbane/10/2007-like (H3N2) • B/Brisbane/60/2008-like (B/Victoria lineage)
Texas Flu Surveillance 2009-2010 Season • Continue funding all packaging, shipping, and testing related to flu surveillance; however, testing may be limited – how? • Increase ILINet participants & culture surveillance sites in selected areas • PCR to continue at LRNs • VTM ordering process? Limits? • To sign up for automatic notification of new flu reports: http://www.dshs.state.tx.us/idcu/disease/ influenza/surveillance/2009/