Download CDC Case Definitions for Pertussis

1
Identification of a Pseudo-Epidemic
of Pertussis
West Virginia 2010-2011
Carrie A. Thomas, PhD
Vaccine-Preventable Disease Epidemiologist
WVDHHR/BPH
[email protected]
06/04/2012
Office of Epidemiology and Prevention Services
Division of Infectious Disease Epidemiology
www.dide.wv.gov
2
West Virginia Regional Map
Region 5
Office of Epidemiology and Prevention Services
Division of Infectious Disease Epidemiology
www.dide.wv.gov
3
Number of Patients <19 Years Old Reported
to WVBPH as Having Pertussis by Quarter
Number of Patients Reported
(2008 through Q3-2011)
200
180
160
140
120
100
80
60
40
20
0
HF-A
Region 5
State (including
Region 5)
108
31
18
Year by Quarter
Office of Epidemiology and Prevention Services
Division of Infectious Disease Epidemiology
www.dide.wv.gov
4
Initial Intervention Attempts
Pertussis PCR Results
 Several attempts by local Percent Positive
Data courtesy of LabCorp
health, local physicians,
Month
HF-A
Overall
and state staff to educate
Oct. 2010
100%
8.7%
providers of HF-A
Nov. 2010
87.5%
22.3%
Dec. 2010
79.4%
17.1%
Jan. 2011
82.4%
9.5%
Feb. 2011
83.9%
8.9%
Office of Epidemiology and Prevention Services
Division of Infectious Disease Epidemiology
www.dide.wv.gov
5
Number of Patients <19 Years Old Reported
to WVBPH as Having Pertussis by Quarter
Number of Patients Reported
(2008 through Q4-2011) - UPDATED
200
180
160
140
120
100
80
60
40
20
0
HF-A
Region 5
State (including
Region 5)
108
75
47
31
18
Year by Quarter
10
Office of Epidemiology and Prevention Services
Division of Infectious Disease Epidemiology
www.dide.wv.gov
6
HF-A Site Visit 12/2011
CDC Case Definitions for Pertussis1
1(http://www.cdc.gov/osels/ph_surveillance/nndss/casedef/pertussis_current.htm)
Probable
Confirmed
In the absence of a more likely
diagnosis, a cough illness lasting ≥2
weeks, with at least one of the
following symptoms:
Acute cough illness of any duration, with
isolation of B. pertussis from a clinical
specimen (culture);
 paroxysms of coughing;
 inspiratory "whoop”;
 post-tussive vomiting;
AND
 absence of laboratory confirmation;
AND
 no epidemiologic linkage to a
laboratory-confirmed case of pertussis
OR
Cough illness lasting ≥2 weeks, with at least
one of the following symptoms:




paroxysms of coughing;
inspiratory "whoop"; or
post-tussive vomiting; AND
polymerase chain reaction (PCR) positive
for pertussis;
OR
Illness lasting ≥2 weeks, with at least one of
the following symptoms:




paroxysms of coughing;
inspiratory "whoop"; or
post-tussive vomiting; AND
contact with a lab-confirmed case of
pertussis Office of Epidemiology and Prevention Services
Division of Infectious Disease Epidemiology
www.dide.wv.gov
7
HF-A Site Visit 12/2011 (cont.)
 Testing methods for confirming a pertussis diagnosis and
strategies for reducing false positive results in PCR testing
 CDC’s Best Practices for Health Care Professionals on the use of
Polymerase Chain Reaction (PCR) for Diagnosing Pertussis
http://www.cdc.gov/pertussis/clinical/diagnostic-testing/diagnosis-pcr-bestpractices.html
 Pertussis data the West Virginia Bureau for Public Health
(WVBPH) has collected over the past 4 years
Office of Epidemiology and Prevention Services
Division of Infectious Disease Epidemiology
www.dide.wv.gov
8
Number of Patients <19 Years Old Reported
as Having Pertussis by Year of Report
(2008 – 10/31/2011*)
Number of Patients Reported
200
180
HF-A
160
140
149
Region 5
120
111
State (including
Region 5)
100
80
60
41
40
20
0
68
14
14
0
2008
0
2009
5
36
59
22
Year
2010
2011*
Office of Epidemiology and Prevention Services
Division of Infectious Disease Epidemiology
www.dide.wv.gov
9
Number of Reported Patients that Do Not
Meet CDC Case Definition for Pertussis
(2008 – 10/31/2011*)
200
Number of Patients
180
Not a Case
160
Case
140
120
82%
100
28%
n=
122
80
60
60%
40
20
0
37%
46%
29%
44%
State Region HF-A
State Region HF-A
State Region HF-A
State Region HF-A
2008
2009
2010
2011*
43%
64%
60%
Year
Office of Epidemiology and Prevention Services
Division of Infectious Disease Epidemiology
www.dide.wv.gov
10
Number of Patients with at Least One
Additional Symptom (2010 - 10/31/2011)
HF-A
n=97
State
n=130
15%
44%
56%
Case
Case
Not a
Case
Not a
Case
85%
Office of Epidemiology and Prevention Services
Division of Infectious Disease Epidemiology
www.dide.wv.gov
11
Number of Patients without One
Additional Symptom (2010 - 10/31/2011)
State
n=26
HF-A
n=107
100%
4%
n=1
Case
Case
Not a
Case
Not a
Case
96%
Office of Epidemiology and Prevention Services
Division of Infectious Disease Epidemiology
www.dide.wv.gov
12
Combined 1/1/2010 – 10/31/2011 data
 HF-A patients had shorter cough duration (14 vs. 29 days;
p<0.0001)
 HF-A patients were younger (3 vs. 6 years; p<0.0001)
HF-A
All other physicians - state
p
% cough
91%
96%
0.01
% cough at final
interview
29%
65%
< 0.0001
Meet CDC case
definitions
25%
66%
< 0.0001
% male
56%
46%
0.04
Office of Epidemiology and Prevention Services
Division of Infectious Disease Epidemiology
www.dide.wv.gov
13
Site Visit Findings
 PCR being used as a screening tool
 Vaccine preparation area located on same countertop
where they stored specimen collection material and
processed specimens for submission




Areas “separated” by line of tape dividing counter in half
Squirting vaccine in air during preparation
Inadequate hand hygiene practices
Inadequate environmental cleaning procedures
 Liquid transport media being used
Office of Epidemiology and Prevention Services
Division of Infectious Disease Epidemiology
www.dide.wv.gov
14
Post-Site Visit Actions
 Provided environmental cleaning and hand hygiene
materials
 HF-A separated vaccine preparation and specimen
collection/processing areas
 Received 2 positive pertussis PCR results as of May
2012 from HF-A
Office of Epidemiology and Prevention Services
Division of Infectious Disease Epidemiology
www.dide.wv.gov
15
Conclusions
 Pseudo-epidemic likely caused by
 Inappropriate use of PCR testing
 Inadequate infection control practices
 Provider education critical to the resolution of the
situation
Office of Epidemiology and Prevention Services
Division of Infectious Disease Epidemiology
www.dide.wv.gov