Value of PCR: A Pertussis Outbreak in a Football Team Sharmila Shah 1, Mohammed Haque 1, John Kornblum 2, Lillian Lee 2, Allison Scaccia 1, Jane R. Zucker 1,3 1: Bureau of Immunization, NYC DOHMH 2: Public Health Laboratory, NYC DOHMH 3: CDC/NIP/ISD

Background of Pertussis Case Reporting in NYC In NYC, the number of reported pertussis cases has been increasing similar to what is being seen nationwide Many of the cases were classified as probable because of the lack of diagnostic information In 2004, NYC DOHMH misdiagnosed 64% of pertussis case reports

Improved Testing for Pertussis The NYC DOHMH, Public Health Laboratory (PHL) had provided DFA testing and cultures for pertussis PCR testing was introduced in 2004

Reported Pertussis Cases by Year: , NYC

Number of Culture and PCR Positive Pertussis Cases, YearPositive Culture Positive PCR Total # Confirmed (C) Total # Probable (P) Total # C& P

Probable and Confirmed Pertussis Cases by Age Category, NYC, 2004(N=196) N=51 N=7 N=70 N=15 N=53

Pertussis Clinical Features, NYC, 2004 (Probable and Confirmed Cases Only) Yes (%)No (%) Cough196(100%)0(0) Paroxysms164(84%)32(16%) Whoop58(30%)137(70%) Posttussive Vomiting 91(46%)105(54%) Apnea69(35%)127(65%)

Objectives To show the value of PCR testing in a pertussis investigation where contacts were either asymptomatic or minimally symptomatic

History of Index Case Index case: 15 year old white non-Hispanic male –Cough onset: , received treatment –Cough duration: 18 days –Symptoms: paroxysms, whoop, posttussive vomiting, and apnea Lab Test: Culture and PCR positive, reported (9/24/04) Contacts identified: – Household contacts: 4 –School contacts: 600 students in the class, none were face to face, no one was coughing But, index case was a member of the football team (46 immediate contacts) and other team members were coughing.

Methods Nasopharyngeal swabs were collected from all the identified close contacts, i.e. all members of the football team Specimens were immediately plated on fresh Bordet-Gengou and Regan-Lowe media Sent to the PHL for PCR, DFA testing and culture

Results A total of 46 team members were tested for PCR, DFA and culture on None met the clinical case definition for pertussis, none had sustained cough 5(11%) had symptoms consistent with URI or catarrhal stage of pertussis

Results Among the 5 symptomatic team members, 4(80%) were positive by both PCR and DFA One patient (20%) who was PCR positive also had a positive culture All asymptomatic children were negative by PCR, DFA and culture

Follow Up 43 contacts had a history of five shot DTaPs The rest of the contacts had history of 3 DTaPs All household and football team contacts received antibiotics after collection of nasopharyngeal swab. Follow up with the school for 21 days for additional cases was conducted; no additional students became ill

Case Definitions For purposes of this investigation and to identify the extent of infection among the football team members a case was defined as: – “any member of the football team with symptoms consistent with the catarrhal stage or paroxysmal stage of illness between and ”.

Sensitivity and Specificity of Testing SymptomsNo Symptoms PCR (+) 40 PCR (-) 141 Sensitivity = 80% Specificity = 100% SymptomsNo Symptoms Culture (+) 10 Culture (-) 441 PCRCulture Sensitivity = 20% Specificity = 100%

Advantage of PCR testing Rapid turnaround time (few hours), which was enhanced its value as a significant tool to: –Identify the extent of this outbreak –Direct broad antibiotic prophylaxis and prevent further transmission

Conclusion Previously vaccinated adolescents may lack typical symptoms of pertussis and for this reason laboratory diagnostic testing may be necessary to confirm infection In our investigation, sensitivity of PCR was substantially higher than for culture Rapid intervention prevented infected students from developing classic cough illness and interrupted further transmission

Special thanks! Christian Oriuwa, Supervisor Queens Field Office Ellen Demott, JFK Quarantine Station, CDC John Bateman JFK Quarantine Station, CDC

Probable and Confirmed Pertussis Cases by Race and Borough, NYC,2004 RaceBronx N(%) Brooklyn N(%) Manhattan N(%) Queens N(%) S. I. N(%) White32(16)34(17)41(21)18(9)15(8) Black19(10)6(3)2(1)4(2)0(0) Asian1(0.5)0(0)2(1) Other0(0)7(4)1(.5)10(5)0(0) Total52(27)47(24)46(24)34(17)17(9)

Probable and Confirmed Pertussis Cases by Borough and Ethnicity, NYC,2004 BoroughHispanicNon HispanicTotal Bronx Brooklyn83947 Manhattan Queens Staten Island Total63(32%)133 (68%)196

Pertussis Complications, 2004, NYC ConditionsYesNo Pneumonia4116 Generalized or Focal Seizures 2194 Encephalopathy0196 Hospitalization45151 Death0196

Detection of B. pertussis Using Real Time PCR Extract bacteria from NP swab into sterile distilled water Boil extract to release DNA Add 5 microliters of boiled extract to PCR assay tube Assay tube contains primers specific for B. pertussis target sequences, PCR enzyme, and substrates

Detection of B. pertussis Using Real Time PCR Set up assay tubes with positive, negative and inhibition controls Place assay tubes in thermocycler to begin PCR Perform 45 cycles of 95 o C for 10 seconds, 55 o C for 10 seconds, and 72 o C for 5 seconds

Detection of B. pertussis Using Real Time PCR Positive control Inhibition control Sample & neg control