Core 3 Update: Epidemiology and Risk Analysis Aron J. Hall, DVM, MSPH Centers for Disease Control and Prevention NoroCORE Full Collaborative & Stakeholder Meeting, Dallas, TX October 30, 2014
Core 3: Purpose and Personnel Purpose: Collect and analyze population data on norovirus disease burden, including epidemiologic attribution, risk, and costs Co-PDs: Aron Hall (CDC), Christine Moe (Emory), Steve Beaulieu (RTI) Collaborators: NC State, Arizona State, U of Cincinnati, FDA, Kaiser Permanente, FoodNet, Veterans Affairs, NVSN, CHOA
Core 3: Activities 3.1: Develop and apply quantitative risk models 3.2: Estimate economic burden of foodborne HuNoV outbreaks 3.3: Estimate endemic norovirus disease burden 3.4: Estimate epidemic norovirus disease burden 3.5: Prepare preliminary norovirus epidemiologic attribution model
Activity 3.3: Estimate Endemic Norovirus Disease Burden Active healthcare-based surveillance for gastroenteritis patients New Vaccine Surveillance Network of pediatric hospitals- Ongoing Passive laboratory-based surveillance of routinely submitted specimens Veterans Affairs Medical Centers (VAMC)- Ongoing Kaiser Permanente (KP) outpatient clinics- Ongoing See poster by Grytdal et al Indirect modeling of national administrative datasets- Completed National Center for Health Statistics Multiple-Cause Mortality Commercial, Medicare, & Medicaid healthcare claims (MarketScan)
Annual Burden (Lifetime Risk) of Norovirus Disease in the United States 570 800 Deaths (1 in 5000 7000) 56,000 71,000 Hospitalizations (1 in 50 70) 400,000 Emergency Dept Visits (1 in 9) 1.7 1.9 million Outpatient Visits (1 in 2) 19 21 million Total Illnesses (~5) Hall 2013a EID
Outpatient and ED Surveillance for AGE in Children Aged <18 years, Vanderbilt Children s Hospital, December 2012-November 2013 (N=1217) Demographics of Study Population Male 633 (52%) White Black Hispanic 718 (59%) 438 (36%) 462 (38%) Stool collected 965 (79%) Median Age 43 months No Virus 60% Norovirus 15% Rotavirus 13% Sapovirus 9% Astrovirus 3% Halasa 2014 IDWeek
Characteristics of Stool Specimens Submitted for Routine Clinical Diagnostics, VAMC, November 2011-October 2012 (N=1160) Patient Age Patient Sex Variable All specimens collected 7 days after onset (%) Under 65 years 615 (53) 65 years or older 545 (47) Male 1093 (94) Female 67 (6) Admission status Inpatient 957 (82) Outpatient 203 (18) Total norovirus positive 50 (4) Norovirus GI positive 8 (16) Norovirus GII positive 42 (84) Grytdal 2014 IDWeek
Estimated Norovirus-associated Incidence, VAMC, November 2011-October 2012 (per 100,000 patients) Patient Type Site Age (years) A B C D < 65 65 Total Outpatient 285 63 307 194 172 200 188 Community-acquired inpatient Hospital-acquired inpatient 9 7 9 31 8 14 11 36 0 28 261 45 66 54 Grytdal 2014 IDWeek
Activity 3.4: Estimate Epidemic Norovirus Disease Burden Characterize the national burden of epidemic norovirus- Ongoing Monitor temporal trends and emergent strain impacts- Ongoing Identify priority settings and populations for interventions- Ongoing
Norovirus Outbreak Surveillance Systems in the United States NORS Epidemiologic surveillance for all enteric disease outbreaks Data on setting, transmission mode, exposures, demographics, outcomes CaliciNet Laboratory surveillance using molecular genotyping of outbreakassociated specimens Data on genotypes to identify new strains and potentially link outbreaks Norovirus Sentinel Testing and Tracking (NoroSTAT) Enhanced reporting through NORS and CaliciNet in five states (MN, OH, OR, TN, WI) Report suspected norovirus outbreaks within 7 days of notification of the outbreak to the state health department See poster by Wikswo et al
Outbreak Surveillance Enhancements Improved NORS data accessibility- Ongoing Data downloaded by state and local users in a variety of file formats and database structures Expansion of public access FOOD tool to include all transmission modes and data visualization Direct NORS data upload from existing state databases- Ongoing Eliminate double entry by state epidemiologists Improve system acceptability and reporting rates Extensive NORS user interface changes- Completed NORS-CaliciNet data integration- Ongoing
Activity 3.5: Prepare Preliminary Norovirus Epidemiological Attribution Model Descriptive attribution of norovirus outbreaks- Ongoing Modes of transmission (e.g., % foodborne) Setting of exposure and food preparation Food commodities and contamination factors Genotype (through NORS-CaliciNet integration) Develop a model to predict the impact of specific interventions on US disease burden- Ongoing
No. of norovirus outbreaks Jan Mar May Jul Sep Nov Jan Mar May Jul Sep Nov Jan Mar May Jul Sep Nov Jan Mar May Jul Sep Nov Norovirus Outbreaks by Month, NORS, 2009-2012 (N=4,318) 350 300 250 200 150 100 50 0 2009 2010 2011 2012 Month-year Hall 2014 MMWR
Setting of Norovirus Outbreaks, NORS, 2009-2012 (N=3,243) Long-Term Care Facilities 59% Restaurants 17% Schools 5% Caterer/Banquet Facility 5% Hospitals 3% Private Residence 2% Daycares 2% Other/Multiple 7% Note: Does not include 44 (1%) norovirus outbreaks meeting VSP posting criteria Hall 2014 MMWR
Transmission Mode of Norovirus Outbreaks, NORS, 2009-2012 (N=4,318) Person-toperson 69% Foodborne 23% Unknown 7% Environmental 0.3% Waterborne 0.3% Hall 2014 MMWR
Norovirus Genotype Distribution by Transmission Route, CaliciNet, 2009-2013 Foodborne Outbreaks (n=449) GII.6 8% GII.3 2% GII.2 3% GII.1 8% GI.7 2% GI.6 11% GII.12 GII.7 5% 3% GI.4 1% GI.3 4% GII.4 53% GII.7 GII.6 1% 4% GII.3 0% GII.2 2% GII.1 6% GI.7 0% GI.6 5% GI.4 1% Odds ratio = 3.0 (95%CI = 2.5 3.7) Person-to-Person Outbreaks (n=2371) GII.12 1% GI.3 2% GII.4 78% Vega 2014 JCM
Predominant Epidemiologic Characteristics of Norovirus Outbreaks by Genotype Characteristic GII.4 Non-GII.4 Seasonality Winter Spring-summer or nonseasonal Setting Healthcare facilities Non-health care (restaurants, schools, etc.) Transmission Person-to-person Foodborne Ages affected 65 years <65 years Severity Elevated rates of hospitalization and death Lower rates of severe outcomes Vega 2014 JCM Leshem 2013 EID Desai 2012 CID Matthews E&I 2012
www.cdc.gov/norovirus
Foodborne Norovirus Outbreaks by State, NORS, 2009 2012 1,008 outbreaks reported by 43 states Median outbreaks per state: 9 (range 1 117) Median reporting rate per million personyears: 0.6 (range 0.05 5.5) Hall 2014 MMWR
Settings of Foodborne Norovirus Outbreaks, NORS, 2009 2012 Sit-Down 77% Fast Food 13% Other 10% Hall 2014 MMWR
Contributing Factors and Foods Implicated in Foodborne Norovirus Outbreaks, NORS, 2009 2012 Factors contributing to contamination reported in 520 (52%) outbreaks 70% implicated infectious food worker as source 54% involved bare-hand contact with ready-to-eat foods Specific food item in 324 (32%) outbreaks 92% implicated foods contaminated during final preparation; 75% were foods eaten raw Single food category identified in only 21% Vegetable row crops (30%) Fruits (21%), Mollusks (19%) Hall 2014 MMWR
Norovirus Vital Signs Report www.cdc.gov/vitalsigns/norovirus/ See poster by Kambhampati et al
Media Impact of Norovirus Vital Signs 30-days Post Release 963 news articles Potential reach of 650M people Worth $5.4M if purchased Outlets included: USA Today, CNN, Huffington Post, Washington Post, NBC Nightly News, FOX News, US News & World Report, Web MD, Yahoo! Health, Medscape 243,207 hits to CDC Vital Signs Norovirus website 2,023 social media posts with potential reach of 22.5M people
Ongoing Activities Improved disease burden estimates Continue direct testing platforms to generate more robust and population-specific incidence estimates Maintain effective platforms for assessment of trends over time and potential impact of future interventions Outbreak surveillance enhancements and attribution Improve reporting to better characterize epidemic norovirus and priority targets for interventions Genotype-specific attribution of outbreaks through integration of NORS and CaliciNet
Questions? Aron Hall (ajhall@cdc.gov) Christine Moe (clmoe@emory.edu) Steve Beaulieu (steveb@rti.org)