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Identification of a Pseudo-Epidemic of Pertussis West Virginia 2010-2011. Carrie A. Thomas, PhD Vaccine-Preventable Disease Epidemiologist WVDHHR/BPH Carrie.A.Thomas@wv.gov 06/04/2012. West Virginia Regional Map. Region 5.
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Identification of a Pseudo-Epidemic of PertussisWest Virginia 2010-2011 Carrie A. Thomas, PhD Vaccine-Preventable Disease Epidemiologist WVDHHR/BPH Carrie.A.Thomas@wv.gov 06/04/2012
West Virginia Regional Map Region 5
Number of Patients <19 Years Old Reported to WVBPH as Having Pertussis by Quarter (2008 through Q3-2011) Number of Patients Reported Year by Quarter
Initial Intervention Attempts Percent Positive Pertussis PCR Results Data courtesy of LabCorp • Several attempts by local health, local physicians, and state staff to educate providers of HF-A
Number of Patients <19 Years Old Reported to WVBPH as Having Pertussis by Quarter (2008 through Q4-2011) - UPDATED Number of Patients Reported Year by Quarter
HF-A Site Visit 12/2011CDC Case Definitions for Pertussis1 1(http://www.cdc.gov/osels/ph_surveillance/nndss/casedef/pertussis_current.htm) Probable Confirmed Acute cough illness of any duration, with isolation of B. pertussis from a clinical specimen (culture); 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 In the absence of a more likely diagnosis, a cough illness lasting ≥2 weeks, with at least one of the following symptoms: • paroxysms of coughing; • inspiratory "whoop”; • post-tussive vomiting; AND • absence of laboratory confirmation; AND • no epidemiologic linkage to a laboratory-confirmed case of pertussis
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 HF-A Site Visit 12/2011 (cont.)
Number of Patients <19 Years Old Reported as Having Pertussis by Year of Report (2008 – 10/31/2011*) Number of Patients Reported Year
Number of Reported Patients that Do Not Meet CDC Case Definition for Pertussis(2008 – 10/31/2011*) Number of Patients 82% n= 122 28% 60% 46% 37% 44% 29% 64% State State State State Region Region Region Region HF-A HF-A HF-A HF-A 2009 2010 2011* Year
Number of Patients with at Least One Additional Symptom (2010 - 10/31/2011) 15% 44% 56% 85%
Number of Patients without One Additional Symptom (2010 - 10/31/2011) 4% n=1 100% 96%
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)
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 Site Visit Findings
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 Post-Site Visit Actions
Pseudo-epidemic likely caused by • Inappropriate use of PCR testing • Inadequate infection control practices • Provider education critical to the resolution of the situation Conclusions