Nosocomial Clostridium difficile Infection (CDI): Things Are Not - - PowerPoint PPT Presentation

Angela Wigmore,

• K. Suh, N. Bruce, G. Garber,
• C. Chambers, Liz Van Horne,
• V. Allen, C. Egan,
• K. Stockton, V. Roth

Nosocomial Clostridium difficile Infection (CDI): Things Are Not Always As They Seem

Disclosure

• None of the authors on this presentation have

anything to disclose

• Clostridium difficile is an anaerobic gram positive spore

forming bacterium

• It can cause a severe inflammatory colonic disease with

a high morbidity and mortality

• Most commonly associated with health care, occurring

in hospitals and other health care facilities

Clostridium difficile

Setting

• The Ottawa Hospital (TOH): A multi site tertiary care

facility with 1,200 beds

• Most acute inpatient care is provided at 2 sites

Civic

Background

• CNISP CDI rates were stable between 1997- 2007

(0.66 and 0.73 per 1000 patient days, respectively)*

• Healthcare – associated CDI is frequent and of

increasing severity

• CDI attributable mortality increased from 1.5% in

1997 to 5.3% in 2011 per 100 HA-CDI cases*

*Public Health Agency of Canada, CNISP, Clostridium difficile Associated Disease (CDAD) Surveillance

Issue

• 2012-2013 we experienced several prolonged
• utbreaks on our in patient units despite

reinforcement of:

• routine practises
• prompt isolation of symptomatic patient
• enhanced environmental cleaning with bleach
• implementation of bedpan liner waste management

transmission persisted

Issue Continued

• In spite the implementation of these measures as

well as the increase in resources and energy the

• utbreaks were not terminated
• Several units continued to have an increase in

nosocomial cases

• Public Health Ontario was asked to conduct a

review

Definition

• Outbreak was defined as 3 or more geographically

clustered cases of laboratory confirmed HA-CDI on

• ne w/u within 7 day or 5 cases within 4 weeks
• Healthcare associated CDI was defined as onset of

symptoms >72 hours after admission or symptoms present on admission with a previous admission in the preceding 8 weeks

Investigation

• Public Health Laboratory performed molecular typing
• f outbreak isolates
• Methodology used was pulse-field gel electrophoresis

(PFGE)

• 41 isolates from 9 different outbreaks involving 48

patients (~3-9/outbreak) were typed

V

CDI CDI CDI CDI CDI CDI CDI CDI CDI

H NAP 4 G L M NAP 1 E NAP11 F

Floor Plan of An Outbreak Unit B

PFGE Typing

Different Same

*Provided by Marina Lombos, Public Health Laboratory, Toronto, Ontario

Results

• NAP-1 strain accounted for 39% of all isolates but was

the predominant strain in only one outbreak

• 16 different PFGE patterns were identified
• A median of 3 PFGE patterns was identified in each
• utbreak (range 2-6)
• Findings suggested that isolates from our outbreaks

at TOH were polyclonal

Outbreak Typing Results

Campus Unit No. patients

• No. samples

typed

• No. unique

strains Predominant Strain General A 5 4 2 none B* 12 9 9

none

C* 9 8 6

none

D 9 8 5

none

E 3 2 2

none

Civic F* 10 10 3

NAP1

TOTAL 48 41 16

NAP1

* 2 outbreaks on each of these units

Lessons Learned

• Things are not always as they seem. HA cases that

appear to be linked were caused by different strains of Clostridium difficile

• In spite of our findings basic infection prevention

measures remain the cornerstone in reducing transmission of Clostridium difficile

Conclusion

• Prevention strategies need to shift with a greater

focus on appropriate antimicrobial use

• Typing did not produce the results we expected

leaving many questions still unanswered

• The epidemiology of CDI in the community also

deserves further study.

Acknowledgements

I would also like to thank and recognize the following individuals:

• Dr Gary Garber
• Cathy Egan
• Liz Van Horne
• Vanessa Allen
• Marina Lombos