Hospital Outbreaks

1. Hospital Outbreaks Allison McGeer Mount Sinai Hospital 416-586-3118 amcgeer@mtsinai.on.ca

2. Outbreaks • Anything out of the ordinary • An increase in the occurrence of a complication or disease above the background rate • A statistically significant increase in the incidence of an infection

3. Why are hospitals a problem? PATHOGENS • They concentrate virulent pathogens ACCESS • By hands on care, they allow transmission of these pathogens • By devices & parenteral therapy, they permit access HOSTS • They admit susceptible hosts (elderly, immunocompromised) • They make them more susceptible (chemotherapy, surgery)

4. Hospital Outbreaks • 1 in 8 patients in Canadian hospitals acquire an infection as a result of their hospital stay • 5-10% of these are part of outbreaks • Rate: 1/10,000 admissions (Wenzel, 1981) 1/12,000 admissions (Haley, 1985) at least an equal number of “clusters”

5. Outbreaks to be prepared for: • MRSA/VRE; S. aureus (nurseries); S. pneumoniae; GAS • P. aeruginosa, Serratia, Salmonella; resistant gram negs (ICU) • Legionella, Mycobacteria, C. difficile • Scabies • Candida, Aspergillus • Influenza, Hepatitis A/B/C, SREV, Adeno

6. Outbreaks to be prepared for: • MRSA/VRE; S. aureus (nurseries); S. pneumoniae; GAS • P. aeruginosa, Serratia, Salmonella; resistant gram negs (ICU) • Legionella, Mycobacteria, C. difficile • Scabies • Candida, Aspergillus • Influenza, Hepatitis A/B/C, SREV, Adeno PEOPLE ARE THE RESERVOIR TRANSMISSION FROM PERSON TO PERSON IS THE PROBLEM

7. “Other” hospital outbreaks • E. coli O157:H7 in a salad served to patients, and in cafeteria • Legionella pneumophila in water supply • Pseudomonas aeruginosa from water/sinks • Ralstonia picketii from contaminated normal saline • Aspergillus fumigatus from an air conditioner • Serratia marcescens blood infections from propofol • Candida spp. from vacuum seals in equipment for preparation of TPN

8. Hospital vs. Community Outbreaks • Reservoir/propagation • Reservoir is people (usually patients) • Propagation is person to person • We provide medical care to patients, as well as outbreak management • Easier to get medical/laboratory information • Differences between goals more evident

9. Preparing for outbreaks - Prevention • Physical structure • Private rooms • Adequate space – between patients, for cleaning • Adequate ventilation • Enough handwashing sinks, well-placed • Design in purchased equipment • Glucometers • Needleless IV systems • Monitors for negative pressure rooms • Machines for cleaning/disinfecting endoscopes/ endoscopes themselves • Cleaning/disinfection/sterilization • Adequate policies • Adherence to policies

10. Preparing for outbreaks - Prevention • Handwashing • Accessibility • Programs for compliance • Education • Aseptic technique • Handwashing • Isolation precautions • Surveillance/reporting

11. Preparing for outbreaks • Detection • surveillance, awareness • culture, lab processing protocols • thresholds, time frames • Preservation of samples/isolates (typing)

12. Preparing for outbreaks • Lines of communication • awareness among administrative staff • media relations • Funding • microbiology lab services • Policies for outbreak management

13. Goals of outbreak investigation/management

14. Cause unknown Control uncertain Disease severe/many cases Something to learn Cause is known Exposure/transmission known Control measures effective Small number/non-severe cases “Nothing to learn” Outbreak types Investigation Management

15. Outbreak investigation • Verify diagnosis • Confirm the outbreak • Develop a case definition • Obtain descriptive epidemiology • Develop a hypothesis • Test the hypothesis • Refine hypothesis/additional studies • Implement control and prevention measures • Communicate findings

16. Hospital outbreak investigation • Verify diagnosis • Confirm outbreak • Perform literature review/call experts • Develop a case definition • Obtain descriptive epidemiology • Open lines of communication • Implement control measures • Consider definitive investigation

17. Initial Investigation • Verify diagnosis • Confirm the existence of a problem • confirm the diagnosis • review existing data (surveillance records, interviews, microbiology records, charts) • Perform a literature review/ call experts • reservoirs, mode of transmission • things that went wrong

18. Initial Investigation • Develop a case definition • microbiology • other lab, radiology • clinical signs/symptoms • other (e.g. skin testing for TB) • set time/place parameters • Identify, count, describe cases • line listing • time/place person • describe nature and severity • plot epidemic curve

19. Initial Investigation • Open lines of communication • consider media strategy • ensure all isolates/potential isolates are saved 7 Implement control measures • enforce existing measures • supplement

20. Initial Investigation 8 Consider definitive investigation • formulate hypotheses • case control/cohort studies • cluster analysis

21. Problem #1 • 3 candidemias on 14th level at MSH in one month • 14th level is gi medicine/general surgery • 68 beds • large oncology/IBD population • 25 pts per month on TPN

22. Problem #2

23. Invasive GAS disease, LTCFs

24. Other presentations/articles • http://www.idready.org/slides/03outbreak-slides.pdf • http://www.dsf.health.state.pa.us/health/lib/health/Outbreak_Investigation.ppt • http://www.wvdhhr.org/idep/PPTs/OutbreakInvestigation.ppt • http://www.cdc.gov/ncidod/eid/vol4no1/reingold.htm