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Prevention of Influenza in Nursing Home Residents: An Update. Suzanne F. Bradley, M.D. GRECC - VAAAHS December 2, 2010. Influenza in LTCF Objectives. Significance of influenza/winter viruses Update on measures to reduce transmission infection control measures vaccination
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Prevention of Influenza in Nursing Home Residents: An Update Suzanne F. Bradley, M.D. GRECC - VAAAHS December 2, 2010
Influenza in LTCFObjectives • Significance of influenza/winter viruses • Update on measures to reduce transmission • infection control measures • vaccination • Antiviral treatment and prophylaxis
Influenza AViral Structure Neuraminidase (N1,N2) Common Human A Viruses H1N1,H3N2, H1N2 Hemagglutinin (H1-H3) RNA RNA transcriptases polymerase structural proteins M2 protein (only on type A)
2009 Influenza A (H1N1) Virus - Evolution Trifonov V et al. N Engl J Med 2009;10.1056/NEJMp0904572
Seasonal Influenza Mortality and Hospitalization Hospitalization per 100,000 population Deaths per 100,000 population <1 <5 1-4 ≥85 ≥85 5-49 5-49 50-64 65-69 70-74 75-79 80-84 50-64 65-59 70-74 75-79 80-84 Age group, years Age group, years Thompson WW, et al. J Infect Dis. 2006;194:(suppl 2):S92-S97.
2009 H1N1Neutralizing Antibodies • Born 1915 or earlier (n=32) • Range 91-101 yrs old • 2-12 yrs in 1918 • 1918 strain Ab (100%) • Mean titer 1:562 (> 1:40) • B cells isolated - functional Ab Yu et al. Nature 2008;455:532 Hancock K NEJM 10.1056/NEJMoa0906453
It is Good to be Old!!! H3N2 H2N2 H1N1 sw H1N1 1957 Year 1918 1968 1977 2001 2009 Age 52 41 32 91 Immunity H1N1 sw With thanks to Ann Falsey
Influenza InfectionPathophysiology Nasopharynx Trachea (ciliated respiratory epithelium) Lungs (rare)
Pathology of Influenza Infection Asymptomatic Symptoms Rapid replication Release/cell killed Bind to respiratory cell Enter the cell short incubation period (24-48 hours) /highly contagious
Influenza in LTCF Detection • Clinical suspicion/flu season • Serology (2 wks) • Surveillance cultures (3-7 days) • Rapid Tests (hours) • EIA, immunofluorescence, PCR • nasopharyngeal secretions
Confirmed InfluenzaPredictive Symptoms Symptom (%) OR (95% CI) P value* T >100F 3.26 (3.87-2.75) <.001 Cough 2.85 (3.68-2.21) <.001 Congestion 1.98 (2.54-1.54) <.001 Weakness 1.54 (2.22-1.07) .008 Anorexia 1.43 (1.86-1.10) .008 * especially if symptoms severe Fever+cough PPV 79% NPV 49% <.001 < 48 hrs Sensitivity 63% Specificity 67% Monto et al. Arch Intern Med 2000;160:3243
Older Hospitalized PtsInfluenza Diagnosis • Epidemic influenza documented • Lab confirmed cases • Symptom triad • T > 38C, cough, illness < 7 days • Flu (58%) vs Non-Flu (18%) • RR 2.99 (95% CI 1.9-4.8) • sensitivity 78%, specificity 73% • PPV 47%, NPV 91% Walsh et al. JAGS 2002;50:1498.
Influenza in LTCFRapid Diagnostics-Calgary • Controlled study use vs non-use • Test all suspected flu cases • Similar influenza attack rates • Outcomes testing vs non-testing • Reduction outbreak 9 vs 16 days, p=.03 • No difference use: amantadine, ATB, labs, isolation, hospitalizations Church et al. CID 2002;34:790.
Influenza in Long-Term CareInterventions • Isolation/Social Distancing symptomatic patients, staff, visitors cough etiquette barrier precautions/PPE • Disinfection fomites, environment,hand hygiene • Antiviral agents treat cases prophylaxis exposed • Vaccination - patients, staff
2009 H1N1 InfluenzaHierarchy for Controls In Healthcare Facilities • Elimination potential exposures -pt admissions - elective procedures - non-essential or ill visitors - send ill HCW home 2. Engineering controls - triage areas/public areas physical barriers (partitions), limit entry separate ill from well, protect pts & HCW - closed suctioning systems - hands-free dispensers, receptacles www.cdc.gov/h1n1 (10/14/09)
2009 H1N1 InfluenzaHierarchy for Controls In Healthcare Facilities 3. Administrative controls/polices -work place practices and polices - policies - vaccination, sick leave for HCW - policies - cough etiquette, hand hygiene, isolation - triage stations to detect the sick - dedicated/essential staff for possible/confirmed flu • Personal protective equipment - lowest priority, last line of defense - not effective if exposures not recognized - adherence incomplete - equipment not used or maintained properly
Influenza IsolationDroplet Precautions Returns! • Standard precautions plus • Large droplets travel ~ 3 ft • Surgical mask within 3 ft pt with RTI sx** • Single room or cohort • Bed placement > 3 ft/curtains • Masks for symptomatic pts outside of the room • Duration isolation 7 days after onset or 24 hrs after fever/sx resolved which ever is longer* * except immunocompromised, ** unless aerosols occur Siegel JD et al. APIC 2007;35:S65-164 Bradley SF. Infect Control Hosp Epidemiol 1999;20:629, www.cdc.gov/flu/professionals/infectioncontrol
Respiratory ProtectionN95 vs Surgical Masks • Small particles ? role in transmission • Ferret/guinea pig models, human outbreaks • Filtration capacity • Surgical masks 4-90% • N95 respirators 95-99% • N95 vs mask efficacy 75% (study retracted) • Limitations • N95s short supply • compliance 30% • N95 no better than masks during H1N1 outbreak/studies • Prioritize use where aerosols likely (bronch, intubation) • Use in addition other preventative measures • CDC issues interim guidance for surgical mask use Shine KI et al. N Engl J Med 10.1056/NEJM p0908437; MacIntyre CRQ et al. ICAAC Abstract K- 1918b, 2009; Loeb M et al. JAMA. 2009;302(17):(doi:10.1001/jama.2009.1466)
Seasonal InfluenzaVaccine 2010-2011 • Killed and Live virus vaccines A/California/7/2009 (H1N1)-like A/Perth/16/2009 (H3N2)-like B/Brisbane/60/2008=like CDC. MMWR 2010;1-61
Influenza in LTCFVaccination 2010-2011 • All persons > 6 months annually • High risk persons should still be targeted • If vaccine in short supply: • Ages 6 mo-4 yrs, > age 50 yrs • Chronic diseases - pulmonary, renal, hepatic, neurologic, hematologic, metabolic (DM) • Immunosuppressed • Pregnancy during influenza season • BMI > 40 • Native Americans MMWR 2010;59:1-62.
Influenza in LTCFVaccination 2010-2011 (Cont) • Residents chronic care facilities • HCW • Caregivers at risk populations
Influenza in the ElderlyNational Health Objective-2010 • > 90% vaccination high risk pt • Vaccination rates > age 65 (%) 1973-1985 22-33 1993* 52 2006-08 66 2009 69 • NH pts vaccinated 1997 64-82% 1998 83% * Medicare benefit initiated
Inactivated VaccinesInfluenza 2010-11 Approved • Afluria> 6 mo • Fluarix> 3 yrs • Agriflu> 18 yrs • Fluzone High Dose> 65 yrs
Influenza in LTCFFluzone High Dose • High-dose Inactivated Vaccine • Trivalent injectable • FDA approved > 65 yrs • 60 g vs 15 g HA per strain • Higher • antibody titers • local injection reactions 36% vs 24% • fever 1.1% vs 0.3% • ? protective flu or pneumonia not known • no recommendation re use Falsey AR et al. J Infect Dis 2009;2009;200:172; MMWR 59:485, 2010.
Influenza Vaccination in LTCFRole of HCW Interventions Cluster RCT - 40 Parisian LTCF (3483 pts) Post interview vaccination yes vs no pt vaccinated84.3% vs 82.5% HCW vaccinated69.9% vs 31.8% OR CI (95%) p value pt mortality all cause 0.80 (0.66-0.96) .02 pt ILI 0.69 (0.52-0.91) .007 HCW sick leave 0.58 (0.36-0.96) .03 Lemaitre M, et al. JAGS 2009;57:1580; Thomas RE et al. Lancet ID 2006;6:273. Potter J et al. J Infect Dis 1997;175:1; Carman WF et al. Lancet 2000;355:93;
Influenza VaccineImproving Compliance • Physician recommendation • Patient reminders • Pre-printed physician orders • Blanket orders • Nurse-initiated • Active declination • National societies endorse mandatory HCW vaccination
Antiviral Resistance Influenza 2009 CDC Influenza Surveillance Report September 26, 2009 CDC guidance 11/24/2010
Seasonal Influenza Rx Hospitalized Patients - Mortality OR P value • Oseltamivir 0.21 .02 • > 65 yrs 0.24 • ICU 10.5 <.001 • Charleson score 1.3 .03 • Days ill PTA 0.51 .03 Rx Started 6% - 24 hours 29% - 48 hours 51% - 72 hours 72% - 96 hours McGeer A et al. Clin Infect Dis 2007 45:1568
Seasonal Influenza in LTCFEfficacy Prophylaxis Risebrough et al. JAGS 2005;53:444. Hirji et al. ICHE 2002;23:604.
Zanamivir (Relenza)Proper Use (10/9/09) • Diskhaler use only • Do not reconstitute in any liquid • Do not nebulize • efficacy, safety, stability not established • Lactose carrier - malfunction ventilator www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlerts
InfluenzaProphylaxis • High risk patients • context of an outbreak • vaccine contraindicated • vaccinated late (Rx 2 wks) • ILI in vaccinated group • poor antibody response • caretakers
InfluenzaProphylaxis • Rx daily for: • duration outbreak ~ 14 days • one week after last case • peak season • unvaccinated • outbreak vaccinated pop. • Rx daily for 2 wks • post-vaccination Bradley SF et al. Infect Control Hosp Epidemiol 1999;20:629
Influenza in LTCFOutbreak - Clinical Definition • Significance of documented flu in the facility? • attack rates 35-40% • case-fatality rates ~ 55% • rapid initiation prophylaxis for the affected ward or entire facility • Normal respiratory infection background rate • 1 case every 7 days per 40-resident ward • Likelihood cases unrelated within 72 hrs • 2 cases ~ 7% • 3 cases ~ 2% • If 2-3 cases in 48-72 hrs? • initiation of isolation procedures • confirmatory rapid testing if feasible in 3-4 pts • assumes sensitivity test ~ 70% • if a single pt + declare an outbreak Hota S et al. Clin Infect Dis 2007;45:1362. www.cdc.com/flu/professionals/infectioncontrol/longtermcare.htm www.health.gov.on.ca/english/providers/pub/pubhealth/ltc_respoutbreak.html
Outbreaks in LTCFWhat if ILI Continues? Falsey AR et al. CID 2006;42:518.
Outbreaks in LTCFNon-Influenzal Illness Caram LB et al., JAGS 2009;57:482.; Boivin G et al. CID 2007;44:1152.; Louie JK et al. CID 2007;196:705.; Hicks LA et al., JAGS 2006;54:284.
Outbreaks in LTCFCo-Circulating Viral Infections 617 residents/13 NH followed 52 wks paired sera/clinical assessments Falsey AR et al. J Am Geriatr Soc 2008;56:1281. Drinka PJ et al. J Am Geriatr Soc 1999;1087.
2009 H1N1 InfluenzaBacterial Co-Infections • Confirmed H1N1 influenza infection • PCR on 77 pt specimens who died • S. aureus, S. pyogenes, S. pneumoniae, H. flu • 22/77 (29%) evidence bacteria infection • 16/21( eligible for 23 valent vaccine • Pneumococcal vaccine! MMWR 2009;58:1071
Influenza in LTCFPriorities in 2010 • HCW vaccination • a patient safety issue • to keep HCW/families healthy & working • Patient vaccination • still a priority • role of high HA vaccine? • Antiviral susceptibility remains an issue • still relying on NA inhibitors • what strain is circulating can’t be known quickly • zanamavir administration an issue
Influenza in LTCFPriorities in 2010 • Isolation continues to be a challenge • clarification droplet precautions/surgical masks • lack of private rooms/baths • cohorting, other strategies may be necessary • emergence of resistance in pts on antivirals? • Diagnostic testing - what role? • rapid accurate PCR tests now available • improve influenza detection? • reduce unnecessary antiviral use? • cost effective? • how often to screen?
Contact Information • For questions about this audio conference please contact Dr. Suzanne Bradley at sbradley@umich.edu • For any questions about the monthly GRECC Audio Conference Series please contact Tim Foley at tim.foley@va.gov or call (734) 222-4328 • To evaluate this conference for CE credit please obtain a “Satellite Registration” form and a “Faculty Evaluation” form from the Satellite Coordinator at you facility. The forms must be mailed to EES within 2 weeks of the broadcast