PANDEMIC INFLUENZA: PPE & RISK TO HOSPITAL WORKERS

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1 Police Officer 1918

2 PANDEMIC INFLUENZA: PPE & RISK TO HOSPITAL WORKERS Dr. Leonard Mermel Professor of Medicine, The Warren Alpert Medical School of Brown University Medical Director, Rhode Island Hospital Dept. of Epidemiology & Infection Control

3 Rhode Island Hospital Influenza Pandemic

4 Nosocomial Influenza Transmission There will be a risk of pandemic influenza transmission in the hospital setting Additional modes of transmission in hospital setting compared to the community setting Community: predominantly droplet spread over 3 ft distance Hospital: in addition to droplet spread, airborne spread beyond 3 ft may occur from aerosol-generating procedures performed on hospitalized patients (opportunistic airborne spread)

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6 NEJM 351;610, 2004

7 Lessons from Nosocomial Spread of SARS to HCWs

8 SARS vs Influenza Reproductive number [R 0 ] = # of secondary cases generated by a single infected patient R o = 2 for influenza * R o = 2-3 for SARS * Ferguson et al, Nature 2005; Anderson, Phil Trans R Soc Lond 2004

9 SARS Infection Risk of HCWs Consistent N-95 respirator use by HCWs for contact with SARS patients was independently associated with reduced SARS risk (OR 0.1, 95% CI ) Teleman et al, Epidemiol Infect 2004

10 Healthcare Worker Perception of Risk Survey of HCWs in NYC Willingness to work (most least): weather emergency (3 ft snow/24 hrs) mass casualty (massive explosion Yankee stadium) environmental disaster (massive fire Fresh Kills Landfill, Staten Island, wind blowing to Brooklyn) chemical terrorism (mass chem release Penn Station) BT (smallpox outbreak, Queens) radiation terrorism (radioactive bomb, Kings Plaza Mall, Brooklyn) untreatable infectious disease outbreak (SARS outbreak at your hospital) Qureshi et al, J Urban Hlth 2005

11 Healthcare Worker Perception of Risk Willingness for HCWs to work correlates with provision of adequate personal protection equipment (PPE) (Shapira et al, Is Med Sci 1991) If you cannot assure safety of HCWs during a pandemic, they will NOT report for work Thus, any pandemic plan for must assure adequate provisions for PPE for HCWs

12 Recommendations Can t identify superspreaders and cannot rule out short-range aerosol transmission during routine care, would err on side of caution during routine care based on perception of risk and possible transmission risk N-95 respirators & eye protection for HCWs when caring for patients during influenza pandemic If forthcoming research determines transmission only by large droplets during routine pt care then could change policy to use masks/eye protection for routine pt care and use N-95/eye protection for aerosolgenerating procedures (eg, suppl O2, nebulized meds, intubation, etc) Gloves for all patient contact Gowns as for standard precautions

13 Pandemic Influenza Research Priorities Determine role of large droplet, short-range and long range aerosol transmission in various healthcare settings & duration of tranmissibility Mouth breathing, coughing, speaking, etc High-flow oxygen delivery Nebulization treatment Intubation & extubation Bi-PAP (bi-level positive airway pressure) Are there influenza superspreaders, and if so, can they be identified a priori

14 Pandemic Influenza Research Priorities Impact of masking pts on transmission risk; if effective, how long before mask needs to be changed Difference in protection of N-95 vs N-100 or other respirators if exposed to human & avian flu aerosols Durability of HCW N-95 & mask efficacy (ie, when to change) Better understand risk of N-95 penetration w/ high inhalation rates of based on different materials & designs Protection from N-95 with and without fit-testing Can technology improve fit to circumvent need for fit-testing

15 Pandemic Influenza Research Priorities Determine best practice for PPE removal to minimize risk of self-inoculation Clarify the role of gowns in influenza transmission risk Determine HCW risk from behavioral science vantage point (ie, transmission involves risk of self inoculation when changing PPE, as well as risk from respiratory route, thus even if mask ok for routine care, risk posed when change to N-95) Is true acquisition risk the same wearing a mask throughout shift and change to N-95 for high-risk procedures vs wearing N-95 throughout shift?

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19 SARS Infection Risk of ICU Nurses: Mask vs N-95 Always wore N-95 vs inconsistently wore N-95 or surg mask RR 0.22 ( ) Always wore surg mask vs inconsistent wore N-95 or mask RR 0.45 ( ) Always wore N-95 vs surg mask RR 0.5 ( ) Always wore gloves vs inconsistently wore gloves RR 0.45 ( ) Always wore gown vs inconsistently wore gown RR 0.36 ( ) Loeb et al, EID 2004

20 SARS Infection Risk of HCWs Only N-95 or mask use was independently associated with reduced risk by logistic regression No HCWs became infected with SARS if they used gowns, gloves, N-95 or mask, and did handwashing vs 100% who omitted > 1 of these measures Seto et al, Lancet 2003

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23 SARS Infection Risk of HCWs No HCWs became infected with SARS if they consistantly wore gowns, gloves, N-95 or mask, and consistant hand washing vs 100% became infected w/ SARS if they omitted > 1 of these measures Seto et al, Lancet 2003

24 SARS Infection Risk of ICU Nurses 13% ICU nurses became infected with SARS if they always wore an N-95 respirator when caring for SARS patients vs 56% who inconsistently wore an N-95 or surgical mask when caring for SARS patients (RR 0.22, 95% CI ) Loeb et al, EID 2004