Surveillance, Epidemiology, and Tracing

Surveillance, Epidemiology, and TracingOverview

Adapted from the FAD PReP/NAHEMS Guidelines: Surveillance, Epidemiology, and Tracing (2014).

• Introduction to when and why• Definitions for technical terms• Organizational structure• Overview of Surveillance Plan

USDA APHIS and CFSPHFAD PReP/NAHEMS Guidelines: Surveillance, Epi, and Tracing - Overview

This Presentation

Surveillance, Epidemiology, and Tracing

Activities


• Foreign animal disease (FAD) – Terrestrial or aquatic disease or pest not

known to exist in the United States• High pathogenicity avian influenza• Foot-and-mouth-disease

– Preventive measures for introduction• Import restrictions• Exclusion activities at borders/ports of entry• Public education programs


Introduction

• FAD investigation– Initiated if an FAD is suspected• Foreign Animal Disease Diagnostician• Guidance Document 12001• APHIS FAD PReP Manual 4-0

• Once an FAD is confirmed– Surveillance, epidemiology, and tracing

response components are activated• Provide real-time understanding• Enable decisions on interventions


Introduction (cont’d)

• Surveillance, epidemiology, and tracing techniques are used to:– Detect cases– Understand disease characteristics– Identify risk factors – Provide information for decision-making– Design and implement control measures– Evaluate the effectiveness of the control

measures implementedUSDA APHIS and CFSPHFAD PReP/NAHEMS Guidelines: Surveillance, Epi, and Tracing - Overview

Purpose

• Surveillance– An intensive form of data recording that

encompasses gathering, documenting, and analyzing data

• Epidemiology– The study of the distribution of disease in

populations and of factors that determine its occurrence

• Tracing – Information gathering on recent movements of

animals, personnel, vehicles, and fomites to identify potential spread of disease, and source


Definitions


Zone/Area DesignationsSummary of Zone and Area DesignationsInfected Zone (IZ) Zone that immediately surrounds an infected Premises

Buffer Zone (BZ) Zone that immediately surrounds an Infected Zone or Contact Premises

Control Area (CA) Consists of an Infected Zone and Buffer Zone

Surveillance Zone (SZ) Zone outside and along the border of a Control Area

Vaccination Zone (VZ) Emergency Vaccination Zone is classified as either Containment Vaccination Zone (typically inside the control area) or Protection Vaccination Zone (typically outside Control Area). This may be a secondary zone designation

• Incident Command System (ICS)– Flexible and scalable • Number and names

of deployed groups will vary

– Planning and Operations Sections

– Incident Action Plan


Incident Command System

Surveillance and Epidemiology


• During an FAD outbreak, surveillance plays a key role in:– Identifying the infectious agent– Determining the scope of the outbreak– Assessing the effectiveness of

eradication and control efforts– Demonstrating a return to disease

free status


Role of Surveillance

• Disease description• Surveillance objectives• Stakeholders and responsible parties• Population description• Case definitions• Data sources• Sampling methods• Diagnostic tests


Surveillance Plan Elements

• Suspect case– Animal showing clinical signs compatible

with FAD• Presumptive positive case– Animal with clinical signs consistent with

FAD and positive test results• Confirmed positive case– Agent has been isolated and identified

using approved tests


Case Definitions

Data Sources• Livestock

producers• Veterinarians• Livestock

organizations• Disease reporting

or notification systems

• Control programs• Sentinel units

• Post mortem diagnostic specimen collection

• Wildlife data


• Considerations for accurate and practical sampling methods:– Sample type– Sample size– Random sampling vs. targeted sampling– Sampling duration and frequency– Sample areas/locations– Availability of diagnostic tests– Pooled testing


Sampling Methods

Types of Specimens• Blood or serum• Skin or vesicular

lesions– Epithelial tissue

or vesicular fluid• Feces, rectal swabs,

cloacal swabs, or genital tract swabs

• Nasal, oral, or oropharyngeal swabs

• Nasal discharge, saliva, tears

• Semen samples• Tissues

– Tonsil, spleen, kidney, liver, lymph node, lung, brain, etc.

• Milk• Environmental

samplesUSDA APHIS and CFSPHFAD PReP/NAHEMS Guidelines: Surveillance, Epi, and Tracing - Overview

• Surveillance– Ongoing data collection, analysis,

interpretation, and dissemination– Used to determine specific actions

for FAD mitigation• Field investigation– Used to collect additional information

about cases identified via surveillance• Disease source, history of disease, etc.


Core Functions

• Analytic studies– Utilizes information gleaned from

surveillance activities and field investigations

– Disease rates and risk factors• Evaluation– Effectiveness– Efficacy– Impact of activities


Core Functions (cont’d)

• Endemic– Present in a population or geographical

area at times• Outbreak– Occurrence of more cases of disease than

expected in a given area, or a specific group, over a particular time period

• Pandemic – An outbreak/epidemic that has spread

over several countries USDA APHIS and CFSPHFAD PReP/NAHEMS Guidelines: Surveillance, Epi, and Tracing - Overview

Disease Occurrence

• A characteristic that is associated with an increase in the occurrence of a particular disease

• May include:– Age– Species– Location– Contact


Risk Factors

• Prevent contact between the FAD agent and susceptible animals– Quarantine, movement controls, biosecurity

procedures, target depopulation• Stop production of FAD agent by

infected or exposed animals– Slaughter or mass depopulation

• Increase the disease resistance of susceptible animals to the FAD agent– Emergency vaccination


Epidemiological Principles

• Generally, disease outbreaks are investigated in three phases:– Descriptive phase– Analytic phase– Intervention phase


Phases of Investigation

Tracing Animal Movements


• Trace-back– Animals, animal products, fomites,

people, vehicles, equipment, and possible vectors that have been moved onto an Infected Premises

– Establish the origin of the agent/hazard


Tracing

• Trace-forward– Animals, animal products, fomites,

people, vehicles, equipment, and possible vectors that have left the Infected Premises


Tracing (cont’d)

• A variety of strategies are required to contain, control and/or eradicate an FAD– Biosecurity– Health and safety– Personal protective equipment– Cleaning and disinfection– Quarantine and movement control


Additional Operational Procedures

• FAD PReP/NAHEMS Guidelines: Surveillance, Epidemiology, and Tracing, and SOP: Surveillance – http://www.aphis.usda.gov/fadprep

• Surveillance, Epidemiology, and Tracing web-based training module– http://naherc.sws.iastate.edu/


For More Information

http://www.aphis.usda.gov/fadprep



http://naherc.sws.iastate.edu/

Authors (CFSPH)• Kerry Leedom Larson, DVM, MPH, PhD,

DACVPM• Glenda Dvorak, DVM, MPH, DACVPM• Janice Mogan, DVM• Courtney Blake, BAReviewers (USDA APHIS VS)• Dr. R. Alex Thompson• Dr. Lowell Anderson• Dr. Steve Goff• Dr. Fred Bourgeois


Guidelines Content

AcknowledgmentsDevelopment of this presentation was by the Center for Food Security and Public Health at Iowa State University through funding from the USDA APHIS Veterinary Services

PPT Authors: Patricia Futoma, Veterinary Student; Kerry Leedom Larson, DVM, MPH, PhD, DACVPMReviewers: Janice Mogan, DVM, Melissa Lang, BS

Surveillance, Epidemiology, and Tracing

Documents

fad prepnahems health

overview surveillance

terrestrial animal disease

aquatic animal disease

tracing activitiesusda

animal health technicians

fad agents

aquatic disease