a case for sherlock: outbreak investigation strategies an air show, four countries and an outbreak
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A Case for Sherlock: Outbreak Investigation Strategies
A Case for Sherlock: Outbreak Investigation StrategiesAn Air Show, Four Countries and an OutbreakAn Air Show, Four Countries and an Outbreak
Baylor University Medical Center
Baylor University Medical Center
Baylor University Medical Center Statistics
Baylor University Medical Center Statistics
37,238 admissions (including newborns) 4,298 babies born 56,570 emergency room visits 254,382 outpatient visits(excluding
home care and emergency department) 1200 licensed beds 1,250 physicians with active privileges 185 medical residents and fellows 5,225 employees
37,238 admissions (including newborns) 4,298 babies born 56,570 emergency room visits 254,382 outpatient visits(excluding
home care and emergency department) 1200 licensed beds 1,250 physicians with active privileges 185 medical residents and fellows 5,225 employees
Test QuestionTest Question
+ =+
Can you determine the correct answer to this question?
Possible AnswersPossible Answers
Meeting Friends for
Bowling league
High School Football
DO NOT ANSWER PHONE!!!
Meeting Friends for
Bowling league
High School Football
DO NOT ANSWER PHONE!!!
Call from LabCall from Lab
We have 2 patients with multi-drug resistant Acinetobacter baumanni SputumBronchial Washing
We have 2 patients with multi-drug resistant Acinetobacter baumanni SputumBronchial Washing
Questions to ask yourselfQuestions to ask yourself
What do I know about Acinetobacter baumanni?
Is this normal sensitivity? Is this the 1st time we have seen
this?What can I do at 4pm on Friday?
What do I know about Acinetobacter baumanni?
Is this normal sensitivity? Is this the 1st time we have seen
this?What can I do at 4pm on Friday?
Acinetobacter baumannii
Acinetobacter baumannii
Characteristics:• Gram negative aerobic coccobacillus• Common in environment worldwide
– Water– Soil– Human normal flora
• Rarely known as disease causing agent
Characteristics:• Gram negative aerobic coccobacillus• Common in environment worldwide
– Water– Soil– Human normal flora
• Rarely known as disease causing agent
Acinetobacter baumannii
Acinetobacter baumannii
• Increasingly identified in nosocomial outbreaks
– Intensive care units– Immunocompromised patients– Ventilator support
“CDC data indicate A. baumannii was responsible for 1% of all nosocomial infections and 4% of nosocomial pneumonia in the United States.”
• Increasingly identified in nosocomial outbreaks
– Intensive care units– Immunocompromised patients– Ventilator support
“CDC data indicate A. baumannii was responsible for 1% of all nosocomial infections and 4% of nosocomial pneumonia in the United States.”
Acinetobacter: Transmission
Acinetobacter: Transmission
Patient-to-patient via transient carriage on hands of HCW
Devices, equipment, or environmental surfaces contaminated from a patient
Patient-to-patient via transient carriage on hands of HCW
Devices, equipment, or environmental surfaces contaminated from a patient
MDR-ABMDR-AB
Resistant to all antibiotics testedVery little risk to healthy peopleCan survive on environmental
surfaces several days
Resistant to all antibiotics testedVery little risk to healthy peopleCan survive on environmental
surfaces several days
Isolate??Isolate??
Meets definition in your policy?Meets definition in your policy?
The decision to investigate is influenced by…
The decision to investigate is influenced by…
morbidity / mortalityunusual presentation – rare
disease, change in pattern, new disease
gut feel…could it be the real thing ….does it look like a duck, quack like a duck….?
morbidity / mortalityunusual presentation – rare
disease, change in pattern, new disease
gut feel…could it be the real thing ….does it look like a duck, quack like a duck….?
Call received from ID Physician
Call received from ID Physician
He has a patient at the rehab hospitalWas in Baylor ICU for 3 weeks
recentlyCulture of sputum shows a totally
resistant Acinetobacter baumanni. “Just thought you would like to know.”
He is really an interesting patient Flown to Baylor from Middle East with
injuries from ejecting from his jet.
He has a patient at the rehab hospitalWas in Baylor ICU for 3 weeks
recentlyCulture of sputum shows a totally
resistant Acinetobacter baumanni. “Just thought you would like to know.”
He is really an interesting patient Flown to Baylor from Middle East with
injuries from ejecting from his jet.
There are now 3 patients reported
Need to act quicklyNot “quick and dirty” but “quick
and clean”No one “right” list, but everyone
needs a checklist to ensure systematic approach and to ensure that you don’t miss any key steps.
Need to act quicklyNot “quick and dirty” but “quick
and clean”No one “right” list, but everyone
needs a checklist to ensure systematic approach and to ensure that you don’t miss any key steps.
Important Checklist Considerations
Important Checklist Considerations
Report to local Health Department, if reportable
Have specimens heldDetermine how high to
communicateDetermine PR, Risk Management
involvementCommunicate, communicate,
communicateWrite final report
Report to local Health Department, if reportable
Have specimens heldDetermine how high to
communicateDetermine PR, Risk Management
involvementCommunicate, communicate,
communicateWrite final report
Case FindingCase Finding
Be systematic and comprehensive in case finding. Case finding is determine the extent of the outbreak (who is affected? are there more cases than those that might have been the first to be reported? what is the geographic extent?)
Line list is like a spreadsheet with each row representing a case; each column is a key variable such as name or initials, date of onset of illness, diagnosis lab confirmed?, age, sex, etc.
Be systematic and comprehensive in case finding. Case finding is determine the extent of the outbreak (who is affected? are there more cases than those that might have been the first to be reported? what is the geographic extent?)
Line list is like a spreadsheet with each row representing a case; each column is a key variable such as name or initials, date of onset of illness, diagnosis lab confirmed?, age, sex, etc.
AAA
CINDEX CASE
4 N – ICU
• Trauma Unit
• Averages 630-670 patient days
• 4 – 4 bed pods, 2 – 3 bed pods
• Construction overhead
• Requires movement of patients away from noise.
Confirm existenceConfirm existence
Is this a cluster or outbreak?Real versus artifact – not all
apparent increases in disease reflect true increases. Some are due to artifacts of reporting – change in diagnostic test or case definition, improved reporting, heightened awareness, etc.
Is this a cluster or outbreak?Real versus artifact – not all
apparent increases in disease reflect true increases. Some are due to artifacts of reporting – change in diagnostic test or case definition, improved reporting, heightened awareness, etc.
2 more patients reported2 more patients reported
AA ACCBF D
Meeting CalledMeeting Called
Chief Nursing Officer ID physician ICU DirectorNursing ManagerDirector, Respiratory TherapyMicrobiology Lab
Chief Nursing Officer ID physician ICU DirectorNursing ManagerDirector, Respiratory TherapyMicrobiology Lab
Agenda for MeetingAgenda for Meeting
What has been reportedBrief education What has been identified so far -
Line ListingControl Measures that must be re-
enforcedHold all specimens for PFGE testingAny ideas of transmission modeDetermine next steps
What has been reportedBrief education What has been identified so far -
Line ListingControl Measures that must be re-
enforcedHold all specimens for PFGE testingAny ideas of transmission modeDetermine next steps
Continue InvestigationContinue Investigation
Index CaseIndex Case
F-16 fighter pilot Instructor for United Arab Emirates
F-16 fighter pilot Instructor for United Arab Emirates
United Arab EmiratesUnited Arab Emirates
Comprised of 7 emirates (states)Abu Dhabi is largestBorders Saudi Arabia and OmanNorth - Iranian military airportTake national defense seriouslyUAE Air Force 65,000 troopsVery well equipped Air Force2005 addition of 80 F-16’s
Comprised of 7 emirates (states)Abu Dhabi is largestBorders Saudi Arabia and OmanNorth - Iranian military airportTake national defense seriouslyUAE Air Force 65,000 troopsVery well equipped Air Force2005 addition of 80 F-16’s
Index Case Index Case
Apparently entered a loop too low or had a density altitude problem
F-16 hit the ground in full burner Pilot ejected Chute didn't have time to fully deploy Injuries included:
Flail chest Broken leg Back fractures Liver laceration etc.
Apparently entered a loop too low or had a density altitude problem
F-16 hit the ground in full burner Pilot ejected Chute didn't have time to fully deploy Injuries included:
Flail chest Broken leg Back fractures Liver laceration etc.
do
Index CaseIndex Case
2-3 Days in Abu Dhabi hospitalAir lifted to London hospital
Wound infected and debridedStop over in Iceland due to change
in conditionArrived at BUMC 1/24/06Discharged to Rehab facility on
2/14/06
2-3 Days in Abu Dhabi hospitalAir lifted to London hospital
Wound infected and debridedStop over in Iceland due to change
in conditionArrived at BUMC 1/24/06Discharged to Rehab facility on
2/14/06
Case DefinitionCase Definition
Standard case definition is essential so that all cases are classified the same way regardless of where they occur and who the investigators are.
Criteria – not only clinical features, but for outbreak need to specify time (have far back do you go to say that a case was part of this outbreak?),
Loose (sensitive) versus tight (specific) case definition – often looser early to capture as many possible cases as possible, then may narrow.
Standard case definition is essential so that all cases are classified the same way regardless of where they occur and who the investigators are.
Criteria – not only clinical features, but for outbreak need to specify time (have far back do you go to say that a case was part of this outbreak?),
Loose (sensitive) versus tight (specific) case definition – often looser early to capture as many possible cases as possible, then may narrow.
Descriptive EpidemiologyDescriptive Epidemiology
Time – begin with describing when people became ill/culture date. Usually displayed graphically with epidemic curve (“epi curve” for short) – histogram (not bar chart) with time on X axis, # cases on Y axis
Place – where were the patients located? Person – who are they? All ages, both
sexes, or restricted to just some groups?
Time – begin with describing when people became ill/culture date. Usually displayed graphically with epidemic curve (“epi curve” for short) – histogram (not bar chart) with time on X axis, # cases on Y axis
Place – where were the patients located? Person – who are they? All ages, both
sexes, or restricted to just some groups?
Prior to Intervention
0
1
2
3
4
5
1/24
/200
6
1/31
/200
6
2/7/
2006
2/14
/200
6
2/21
/200
6
2/28
/200
6
3/7/
2006
3/14
/200
6
3/21
/200
6
Nu
mb
er o
f C
ases
AA ACCBF D
4T
F G H I K
AA ACCBF
D
D
4W
E J L
MDR-ABCulture Source
0
2
4
6
8
10
12
14
16
18
Nu
mb
er
Routine Surv.
Surv. 5 2
Routine 11 8 5 4
Sputum Wound Urine Blood
MDR-AB Cultures by Date
0
1
2
3
4
5
1/24
/200
6
1/31
/200
6
2/7/
2006
2/14
/200
6
2/21
/200
6
2/28
/200
6
3/7/
2006
3/14
/200
6
3/21
/200
6
3/28
/200
6
4/4/
2006
4/11
/200
6
4/18
/200
6
4/25
/200
6
5/2/
2006
5/9/
2006
5/16
/200
6
Nu
mb
er
Intervention
Implement Control Measures
Implement Control Measures
Eliminate the source Interrupt mode of transmissionReduce susceptibility
Eliminate the source Interrupt mode of transmissionReduce susceptibility
Control MeasuresControl Measures
Maximum Isolation PrecautionsGowns and gloves on entry
Hand Hygiene..Hand Hygiene..HHCohort Patients with MDR-AB
Use reverse isolation for non MDR-ABTerminal Cleaning of RoomsEvaluation of common processesSurveillance cultures of patients
Maximum Isolation PrecautionsGowns and gloves on entry
Hand Hygiene..Hand Hygiene..HHCohort Patients with MDR-AB
Use reverse isolation for non MDR-ABTerminal Cleaning of RoomsEvaluation of common processesSurveillance cultures of patients
1
2
208
763
14
13
421
11
23
24
18
10 12
15 16
5
2219
17OR
ET
2526
27
Transmission Matrix – Spot Map
Baylor University Medical Center Dallas
Rep-PCR Typing Results 28-Apr-06
Culture by Date
0
1
2
3
4
5
Cultu
re P
ositi
ve
Intervention New Strain
One Year LaterOne Year Later
ConclusionConclusion
Investigation usually need to be done quickly, and always needs to be done well
Know your roleUse systematic approachKeep each step simple and
manageableCommunicate findings
Investigation usually need to be done quickly, and always needs to be done well
Know your roleUse systematic approachKeep each step simple and
manageableCommunicate findings
Acinetobacter OutbreaksAcinetobacter Outbreaks
Judy Prescott RN, BSN, CICJudy Prescott RN, BSN, CICBaylor University Medical Center
Dallas, Texas214-820-3456
Baylor University Medical CenterDallas, Texas214-820-3456