Enhanced Pertussis Surveillance

Enhanced Pertussis Surveillance (EPS) is built upon the existing National Notifiable Diseases Surveillance System for pertussis in seven states participating in the Emerging Infections Programs and is characterized by improved completeness and quality of data, augmented data collection and routine isolate collection. Following the identification of a pertussis case, a standardized case report form is completed using information collected during patient and physician interview. Isolates are collected, when available, and routinely shipped to CDC for further laboratory characterization. Because the number of pertussis isolates available for laboratory characterization has declined nationally, EPS sites have incorporated methods to increase isolate collection in their catchment areas, ranging from the establishment of sentinel clinics to promoting free, centralized testing at state public health laboratories.

While the primary objective of enhanced pertussis surveillance is to collect epidemiologic data and isolates from cases of Bordetella pertussis, the EPS system is also capturing case data and isolates for other Bordetella species, including B. parapertussis, B. bronchiseptica, and B. holmesii. When available, epidemiologic information on these other Bordetella species will be incorporated into the enhanced pertussis surveillance dataset and isolates will be submitted to CDC.

Sites are encouraged to incorporate methods to increase the yield of identified pertussis cases in the catchment area. Methods for improving case ascertainment include encouraging providers to submit specimens directly to state public health laboratories for centralized testing, as well as active education of providers and public health personnel within the catchment area about pertussis and the goals of EPS.

Case Definition

• Clinical Case Definition
  • In the absence of a more likely diagnosis a cough illness lasting ≥2 weeks with one of the following symptoms:
    • Paroxysms of coughing, OR
    • Inspiratory "whoop," OR
    • Posttussive vomiting, OR
    • Apnea (with or without cyanosis) (FOR INFANTS AGED < 1 YEAR ONLY)
• Confirmed Case
  • Acute cough illness of any duration, with isolation of B. pertussis from a clinical specimen, OR
  • A case that meets the clinical case definition AND is polymerase chain reaction (PCR) positive for pertussis, OR
  • A case that meets the clinical definition AND had contact with a laboratory-confirmed case of pertussis.
• Probable Case
  • Meets the clinical case definition, is not laboratory confirmed, and is not epidemiologically linked to a laboratory-confirmed case, OR
  • FOR INFANTS AGED < 1 YEAR ONLY:
    • Acute cough illness of any duration with at least one of the following signs or symptoms:
      • Paroxysms of coughing, OR
      • Inspiratory "whoop", OR
      • Posttussive vomiting, OR
      • Apnea (with or without cyanosis)

      AND

    • PCR positive for pertussis, OR
  • FOR INFANTS AGED < 1 YEAR ONLY:
    • Acute cough illness of any duration with at least one of the following signs or symptoms:
      • Paroxysms of coughing, OR
      • Inspiratory "whoop", OR
      • Posttussive vomiting, OR
      • Apnea (with or without cyanosis)

      AND

    • Contact with a laboratory-confirmed case of pertussis

Program Objectives

• To determine the incidence and epidemiologic characteristics of B. pertussis
• To characterize the molecular epidemiology of circulating strains of B. pertussis
• To determine epidemiologic and molecular characteristics of other Bordetella species (B. parapertussis, B. bronchiseptica, and B. holmesii)
• To monitor the impact of pertussis vaccines
• To provide an infrastructure for additional special studies including those aimed at evaluating B. pertussis prevention and control strategies