title: Pertussis in Missouri: evaluation of nasopharyngeal culture, direct fluorescent antibody testing, and clinical case definitions in the diagnosis of pertussis.
abstract: No diagnostic test for pertussis in routine use in the United States has both high sensitivity and high specificity. During a statewide increase in the incidence of pertussis in Missouri, we studied the clinical features of 153 patients with suspected pertussis in the Greater St. Louis area from whom a specimen for pertussis culture had been taken between 15 May and 19 September 1989. In this cross-sectional study, nasopharyngeal cultures were more likely to be positive for persons whose specimens were collected < 21 days after cough onset (adjusted rate ratio [RRa] and 95% confidence interval = 3.4; 1.5-8.0) and who were not receiving erythromycin/sulfamethoxazole prior to the culture [RRa = 5.8; 0.8-40.6], who had received fewer than three prior doses of pertussis vaccine [RRa = 1.8; 0.8-4.2], and whose specimen was in transit to the laboratory for < 4 days [RRa = 2.0; 0.8-5.5]. Among children < 5 years of age, spasmodic cough plus a lymphocytosis of > 10,000/mm3 was the acute symptom complex associated with the highest predictive value for a positive culture result (67%). Cough for > or = 14 days plus whoop was sensitive (81%) and specific (58%) for identifying children with culture-confirmed pertussis. Direct fluorescent antibody staining performed well as a screening test for pertussis but requires substantial commitment of personnel and resources. In the absence of a positive culture result, clinical case definitions should be used for decision making (e.g., initiation of antimicrobial therapy and routine case reporting).
authors.affiliation: Division of Immunization, Centers for Disease Control, Atlanta, Georgia 30333.
authors.forename: P M
authors.initials: PM
authors.lastname: Strebel
authors.forename: S L
authors.initials: SL
authors.lastname: Cochi
authors.forename: K M
authors.initials: KM
authors.lastname: Farizo
authors.forename: B J
authors.initials: BJ
authors.lastname: Payne
authors.forename: S D
authors.initials: SD
authors.lastname: Hanauer
authors.forename: A L
authors.initials: AL
authors.lastname: Baughman
mesh_terms: D000293:Adolescent; D001431:Bacteriological Techniques / Q000706:statistics & numerical data; D001886:Bordetella pertussis / Q000276:immunology / Q000302:isolation & purification; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003951:Diagnostic Errors; D004812:Epidemiologic Methods; D005069:Evaluation Studies as Topic; D005260:Female; D005455:Fluorescent Antibody Technique / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D008297:Male; D008923:Missouri / Q000453:epidemiology; D009305:Nasopharynx / Q000382:microbiology; D012680:Sensitivity and Specificity; D014917:Whooping Cough / Q000175:diagnosis* / Q000453:epidemiology