Influenza Pandemic, 1957
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TM Real-Life Public Health According to Sir Mick “No, you can't always get what you want You can't alwayygs get what you want You can't always get what you want… TM …And if yyyou try sometime you find You get what you need….” Well, not always…Sometimes you don’t ggypet what you expect or what you want or what you need! TM The H1N1 Response in the United States Surprise, Uncertainty and Too Little Information Peter Houck, MD CDC Division of Global Migration and Quarantine Mexico City, June 2009 TM Outline • What we expppected for a pandemic • How we had planned to respond • What we actually saw and did • What we are planning TM What Did We Expect? TM Previous Influenza A Pandemics • 1918-19, "Spanish flu" (H1N1) • 20-50M died world-wide (~500K in U.S.) • ~50% of deaths in young, healthy adults • Hemorrhagic pneumonia • 1957-58, "Asian flu" (H2N2) • ~70,000 attributable deaths in U.S. • 1968-69, "Hong Kong flu" (H3N2) • 34K excess U.S. deaths TM Pandemic Severity Index 1918 1957, 1968 TM Influenza Pandemic, 1957 TM TM Pandemic Intervals Inter- Pandemic Pandemic Alert Period Pandemic Period WHO Period Phase 1 2 3 4 5 6 New Domestic Suspected Confirmed First Widespread Animal Human Human Human Outbreaks Spread Throughout United States Recovery Outbreak in At- Outbreak Outbreak Case in Overseas USG Risk Country Overseas Overseas N.A. Stage 0 1 2 3 4 5 6 “Mitigate” “Contain” “Quench” CDC Investigation Recognition Initiation Accel Peak Decel Resolution Interval TM Most likely candidate for next pandemic influenza? Was thought to be influenza A H5N1 TM How Did We Plan to Respond? TM Layered Defense Against a Pandemic • Quarantine and isolation • Health screening at ports of entry • Distribution of inbound flights • En route screening • Health screening at ports of embarkation • Possible travel restrictions from affected regions • Containment at source: travel restrictions, antivirals, quarantine, and isolation (World Health Origin of Organization Rapid Reaction) Pandemic TM Screening at Entry TM David Fitzsimmons, Arizona Daily Star, 4/22/03 U.S. Risk-Based Border Strategy (RBBS) TM Public Health Primary Screening 1. Visual exam fffor obvious signs of illness 2. Review Health Declaration 3. Interview (follow up questions to traveler , if indicated) 4. Check results of thermal scanning device, if used 5. Decide if traveler is suspect ill or if presumed well If traveler is suspect ill: If traveler is presumed well: • Iden tify l ong t erm cont act s of suspect ill traveler • Send the presumed well and • Escort suspect ill traveler and short term contacts to the flight any long term contacts to Public group waiting area (cohort area) Health Secondary Screening TM Visual Inspection TM Scott Stantis, The Birmingham News, 4/2/03 Draft Health Declaration TM Clinical Influenza Definitions vs. Laboratory CfitiiHConfirmation in Househ hldPltiold Population Definition Sens Spec # cases 1. Fever 38C or 2 of symptoms * 0.57 0.81 62 2. At least 2 of symptoms † 0.57 0.90 37 3. Fever ‡ plus cough or sore throat 0.48 0.97 17 4. Fever ‡ plus cough or runny nose 0.48 0.98 16 5. Fever ‡ only 0480.48 0980.98 15 * Symptoms are headache, runny nose, sore throat, aches or pains in muscles or joints, cough, or fatigue. † Symptoms are fever, cough, headache, sore throat, aches or pains in muscles or joints. ‡ Temperature > 37.8C. Cow ling e t a l. PL oS ONE . 2008 ;3 :e 2101. TM Estimating Temperature with Thermal I magi ng 37oC tympanic 39oC tympanic Image from McBride et al, 2007 Images from Ng et al, 2004 TM Advantages of ITDS for Mass FSFever Screeni ng • RidRapid • High volume • Non-contact • Non-invasive • Objective TM Disadvantages of ITDS for Mass FSFever Screeni ng • Personnel requirement – 100–500+ to run system at 20–25 IPOE – Trainers – Technicians – Used when human resources will be very limited • Delay to travelers • Space requirements • Low accuracy and precision – False positives and negatives TM Limitations of ITDS for Influenza SiScreening • Detect fever, not infections! • Cannot detect incubating or afebrile ifinfect tdidiidled individuals (l ow sensiti itiit)vity) • Cannot distinguish infection of interest from other febrile conditions (low sppy)ecificity) • Results have low predictive value TM Public Health Secondary Screening (PHSS) Evaluate risk of potentially ill travelers • Perform epidemiological and physical exam • Confirm suspect ill • Determine who may have been exposed • Isolate ill persons, if necessary • Quarantine contacts , if necessary • Return other travelers to the Flight Group Waiting Area (Cohort Area) TM Number of Persons Entering the United States, 2008* Annual Port Daily (()millions) Air 223,000 81 Sea 71, 000 26 Land 787,000 293 Total 1,081,000 400 *Seaport data is based on 2005 data, the latest available from the Department of Transportation TM CDC Quarantine Stations 2008 Jur is dic tions AK ME Seattle Minneapolis Chicago VT Anchorage NH WA MT ND MA Boston Detroit RI MN NY CT MI WI New York OR ID SD PA NJ Newark WY MD DE IA OH Philadelphia NE No.CA IN WV IL NV Washington, D.C. VA San Francisco UT CO KS MO KY NC TN So.CA OK Dallas SC AR Atlanta AZ NM Los Angeles North TX AL MS GA San Diego West TX East TX LA El Paso FL Houston Miami Honolulu GU HI PR San Juan CDC Quarantine Station TM Pandemic Intervals Inter- Pandemic Pandemic Alert Period Pandemic Period WHO Period Phase 1 2 3 4 5 6 New Domestic Suspected Confirmed First Widespread Animal Human Human Human Outbreaks Spread Throughout United States Recovery Outbreak in At- Outbreak Outbreak Case in Overseas USG Risk Country Overseas Overseas N.A. Stage 0 1 2 3 4 5 6 “Mitigate” “Contain” “Quench” CDC Investigation Recognition Initiation Accel Peak Decel Resolution Interval TM “Community Mitigation Strategies” • Isolation and treatment of ill persons • Voluntary home quarantine of household contacts • School and childcare dismissal plus social distancing • Workplace and community social distancing TM Community Mitigation by Severity Category Pandemic Severity Index Interventions by Setting 1 2 and 3 4 and 5 Home Voluntary isolation of ill at home (adults Recommend Recommend Recommend and children); combine with use of antiviral treatment as available and indicated Voluntary quarantine of household members in homes with ill persons (adults and children); consider Generally not combining with antiviral prophylaxis if Consider Recommend recommended effective, feasible, and quantities sufficient School Child social distancing –dismi ssal of st ud ent s f rom sch ool s Generally not Consider: Recommend: and school-based activities, and recommended ≤ 4 weeks ≤ 12 weeks closure of child care programs TM –reduce out-of-school contacts and Generally not Consider: Recommend: What are Our Goals? 1. Delay disease transmission and outbreak peak 2. Decompress peak burden on healthcare infrastructure 3. Diminish overall cases and health impacts Pandemic outbreak with no intervention # 1 #2# 2 Daily Cases Pandemic outbreak With intervention # 3 Days since First Case TM Excess P&I mortality over 1913-1917 baseline, Philadelphia & St. Louis, 1918 TM (from Hatchett, 2007) What Did We Actually See and Do with Novel Influenza A (H1N1)? TM TM TM The Disease was Already in the US When W e D et ect ed It • Entryyg screening at borders wouldn’t help • Was it arriving in US by aircraft? • Severity? TM At International Points of Entry We Did What W e Al ways D o • Customs/immigration/crew report illness • Quarantine staff evaluate ill passengers • Early in outbreak some contact tracing • Education of travelers • No new screening activities • No exit screening TM Health Alert Poster Health Alert Posters at the El Paso Airport TM THAN Yellow TM g Domestic Travelers, Reported to the Quarantine Activity Reporting System, April 1 - May 31, 2009 (n=107) 10 9 First case of confirmed 8 nove l H1N1 influenza in a ss 7 traveler reported to 6 CDC 5 e-Traveler ss 4 # of Ca # of 3 2 1 0 6 3 1 8 4/2 4/9 5/7 /14 4/1 4/2 4/30 5 5/2 5/2 Date of Travel Confirmed Probable Suspect TM Meanwhile…Community Mitigation • Voluntary isolation • Education about handwashing, covering coughs , stay home • Develop guidance documents • ShSchool cl osure TM TM Severity of Disease Was Not Clear • Looked like very severe disease in Mexico • Mild disease in US • What to do?????????? TM TM TM MMWR Weekly May 8, 2009 /58(17);453/58(17);453--458458 www.cdc.gov/H1N1flu 14 schools closed due to H1N1 in 4 The closures impacted 8075 students and 613 teachers 12 schools reopened in MA, NJ, and NY affe Division of Global Migration and Quarantine School Dismissal, United States, 4/29 – 5/27, 2009 500000 Novel Influenza A (H1N1) - 29 May 2009 450000 400000 350000 300000 states today: MA, NY, TX, and WA ffected (Red) B A 250000 A 200000 468,282 Students 150000 329,834 100000 cting approx. 5035 students and 471 teachers 245,449 50000 169,000 369,237 A. B. 4/28 School dismissal guidance (7 days) 298 433 104 726 0 533 C. 5/1 School dismissal guidance (14 days) 55,765 5/5 School dismissal guidance rescinded 28-Apr 589 29-Apr 30-Apr C 197,985 Source: ED and CDC1-Ma Confirmedy School Closi 318 4-May 118,033 5-May 166 6-May 7-May 61697 75 1500 8-May 5 11-May 1300 Students Affected 13 4838 Date 15-May 24 1100 ng Reports released18-M eachay weekday at 2:00pm36 900 19-May 60 Clo Schools Schools Closed 42052 78 20-May 700 49,893 s 21-May s 32 (Blue) ed 500 22-May 29 300 26-May 13933 14 8075 27-May 100 28-May -100 Public Health Research • Intense investigggation of first four flights with confirmed H1N1 case passengers • Investigggation of outbreak