FoodCORE NOU Metrics

NOU metrics apply to Norovirus, Other Etiology (not Norovirus, Salmonella, Shiga toxin-producing Escherichia coli (STEC), Listeria, Shigella, or Campylobacter), and Unknown Etiology. The FoodCORE performance metrics are a list of measurable activities covering diverse aspects of outbreak response. These activities span from outbreak surveillance and detection through investigation, response, control, and prevention measures. Using the metrics, each center provides data about the burden, timeliness, and completeness of foodborne disease activities related to the key areas of activity. Data for all years of the FoodCORE program are available.

Download: NOU Rationale and Intent [PDF 8 pages]

NOU Metrics

1. Measure of Investigations
   1. Total number of investigations¹
   2. Total number of foodborne or point-source investigations¹
   3. Total number of person-to-person investigations¹

Laboratory-based Metrics

2. Measures for laboratory testing
   1. Measures of investigations with clinical specimens collected and submitted to lab
      1. Number and percent of all investigations with clinical specimens collected and submitted to any laboratory (PHL and clinical)
      2. Number and percent of all investigations with clinical specimens collected and submitted to PHL¹
   2. Number and percent of all investigations where submitted clinical specimens  were tested for GI viruses at the PHL¹
      1. Number and percent of all investigations where GI viral testing of specimens included testing for norovirus by real-time RT-PCR at the PHL¹
         1. Number and percent of all investigations with two or more specimens confirmed positive for norovirus by conventional RT-PCR at the PHL where at least one specimen was sequenced and uploaded to CaliciNet¹
            1. Time from first norovirus detection at the PHL via conventional RT-PCR to upload of sequence to CaliciNet¹
      2. Number and percent of all investigation where GI viral testing of specimens included  testing for other viruses (e.g., sapovirus, astrovirus, rotavirus, adenovirus) at the PHL
   3. Number and percent of all investigations where clinical specimens were tested for pathogenic bacteria or their toxins, antigens, or specific antibodies at the PHL¹
      1. Number and percent of all investigations where bacterial testing of specimens included culture-based diagnostics at the PHL
      2. Number and percent of all investigations where bacterial testing of specimens included non-culture-based diagnostics at the PHL
   4. Number and percent of all investigations where clinical specimens were tested for parasites at the PHL¹

Epidemiology-based Metrics

3. Measures for identified foodborne or point-source investigations with epidemiologic activity or action
   1. Number and percent of foodborne or point-source investigations with exposure assessments conducted¹
   2. Number and percent of foodborne or point-source investigations where an analytic epidemiologic study was conducted¹
4. Number and percent of foodborne or point-source investigations with suspect vehicle/source identified¹
5. Number and percent of foodborne or point-source investigations with confirmed vehicle/source identified¹
6. Measures for foodborne or point-source investigations with an identified vehicle/source where control measures or public health actions were taken
   1. Number and percent of foodborne or point-source investigations with exclusion of a(an) ill person(s) from high-risk setting
   2. Number and percent of foodborne or point-source investigations with remediation or closure of an establishment linked to illness
   3. Number and percent of foodborne or point-source investigations with educational campaigns during outbreaks (beyond individual case education)
   4. Number and percent of foodborne or point-source investigations with media or public messaging (web updates, press release, etc.)
   5. Number and percent of foodborne or point-source investigations with regulatory action (recall, hold, etc.)
7. Number and percent of foodborne or point-source investigations with link to a common location of exposure (e.g. restaurant, food establishment, nursing home, etc.) where an on-site environmental health assessment was conducted¹
8. Number and percent of foodborne or point-source investigations where food or environmental sample was collected for testing¹
9. Number and percent of foodborne or point source investigations where environmental health, agriculture, regulatory, consumer protection, or food safety program staff were contacted
10. Number and percent of outbreaks where NORS form completed¹

NOTE: ¹Minimum reporting requirement for FoodCORE Centers

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Definitions

Other Etiology: Enteric illness with determined etiology that is not Salmonella, Shiga toxin-producing Escherichia coli, Listeria, Shigella, Campylobacter, or norovirus.

Unknown Etiology: Enteric illness with no determined/identified etiology from any of the case, product, or environmental testing to indicate the etiologic agent. This can be because no specimen or sample yielded an isolate or other positive result, and would also include investigations where no specimens or samples were collected.

Foodborne or Point-source Investigation: Epidemiologic activity in response to cases where there is indication of non-person-to-person transmission of a similar enteric illness. This includes investigations where there are demographic or epidemiologic indications of a common, point-source of infection even without laboratory subtyping data to link cases.

Specimens: This will include all clinical specimens submitted to PHL.

Samples: This will include all non-clinical, samples (food, environmental, etc.) submitted to PHL.

Exposure assessment: To include an interview (of any format) that assesses exposures prior to onset of illness, via an open-ended exposure history, or via a list of potential exposures. The key factor to be considered an exposure history is an interview that goes beyond assessment of high-risk settings and prevention education to ascertain food consumption/preference, or other exposure data.

Analytic epidemiologic study: A systematic, statistical analysis against a comparison group or within a cohort to test a hypothesis

Suspect norovirus or other etiology outbreak: If there are not sufficient specimens or samples to classify an outbreak as a confirmed norovirus or other etiology, but the available data (testing, epidemiologic data such as signs, symptoms, and incubation period) indicate an etiologic agent, an investigation should still be classified under norovirus or other etiology, as appropriate, for metrics reporting.

Confirmed norovirus outbreak: Outbreak with two or more clinical specimens positive for norovirus by RT-PCR, EM, or EIA.

Confirmed other etiology outbreak: For most etiologic agents, CDC considers an outbreak to have a confirmed etiology if there are two or more lab-confirmed cases. However, in botulism, marine toxins, and other chemical outbreaks, the definition of a confirmed etiology is not as strict. Since botulism, marine toxins, and other chemical outbreaks have such distinct clinical symptoms, a physician’s diagnosis is often sufficient and laboratory confirmation is not necessary. Therefore, for such outbreaks, CDC would consider it a confirmed etiology outbreak if there is at least 1 probable case (based on clinical symptoms). (See also: Other Etiology definition above)

All measurements of time are in median days: Measurements will exclude weekend days. For laboratory time measurements, only isolates subtyped at the PHL should be included.

Vehicle/Source Identified:

SUSPECT vehicle/source investigations: Investigations of infection where investigational and/or laboratory data indicate a likely vehicle/source of infection without confirmation: vehicle/source is a known risk factor, established errors in food preparation, or reported consumption by a high proportion of cluster-associated cases.

CONFIRMED vehicle/source investigations: Investigations of infection where the etiologic agent has either been identified from the vehicle/source, or the vehicle/source has been statistically implicated in an analytic study.

Control measure: to include interventions such as exclusion of an ill person(s) from high risk setting, remediation or closure of an establishment linked to illness, educational campaigns during daycare outbreaks, etc. To be considered a control measure, activities should extend beyond the routine educational component of an interview or exposure assessment.

Public health action: to include media, public messaging (web updates, press release, etc.), or regulatory action (recall, hold, etc.). To be considered a public health action, activities should extend beyond the routine investigation activities and reach at-risk individuals beyond identified cases. A public health action should be included in the metrics if the FoodCORE Center was directly involved in the action, or is aware that a public health action was taken during a multijurisdictional investigation. For example, if CDC produces public messaging during a multistate outbreak investigation that a FoodCORE Center is involved in, that investigation would be associated with a public health action for the purposes of the metrics.