public health information network (phin) series i is for epi epidemiology basics for...

Public Health Information Network (PHIN)

Series I

is for Epi

Epidemiology basics for non-epidemiologists

Series Overview

Introduction to:

• The history of Epidemiology

• Specialties in the field

• Key terminology, measures, and resources

• Application of Epidemiological methods

Series I Sessions

Title Date

“Epidemiology in the Context of Public Health”

January 12

“An Epidemiologist’s Tool Kit” February 3

“Descriptive and Analytic Epidemiology”

March 3

“Surveillance” April 7

“Epidemiology Specialties Applied” May 5

Session I – V Slides

VDH will post PHIN series slides on the following Web site:

http://www.vdh.virginia.gov/EPR/Training.asp

NCCPHP Training Web site:

http://www.sph.unc.edu/nccphp/training


http://www.sph.unc.edu/nccphp/training

Site Sign-in Sheet

Please submit your site sign-in sheet andsession evaluation forms to:

Suzi SilversteinDirector, Education and Training

Emergency Preparedness & Response Programs

FAX: (804) 225 - 3888

Series ISession IV

“Surveillance”

What to Expect. . .

TodayIntroduction to the applications, limitations, and interpretation of public health surveillance data

Session Overview

• Introduction to Public Health Surveillance– Passive, active, and syndromic surveillance– VA communicable disease law– Paper-based surveillance of reportable diseases– Applications and limitations

• Federal Public Health Surveillance– CDC’s role– Data sources– Surveillance reporting examples

Session Overview (cont’d.)

• Techniques for Review of Surveillance Data– Considerations when working with surveillance data– Access data sources for rate numerators and

denominators– Descriptive epidemiology– Graph and map surveillance rates

Today’s Learning Objectives

Upon completion of this session, you will:

• Recognize the applications and limitations of current public health surveillance practices

• Understand the function of three different types of surveillance: active, passive, and syndromic

• Be familiar with federal public health surveillance systems relevant to epidemiology programs

Today’s Learning Objectives

• Understand the reciprocal pathway of data exchange through county, state, and federal surveillance efforts

• Be familiar with the Virginia paper-based surveillance system for reportable diseases

• Recognize the potential benefits of National Electronic Disease Surveillance System (NEDSS) implementation in Virginia

• Recognize the utility of Epi Info software for surveillance data analysis

Today’s Presenters

Amy Nelson, PhD, MPHConsultantNCCPHP

Lesliann Helmus, MSSurveillance ChiefDivision of Surveillance and InvestigationOffice of Epidemiology, Virginia Department of Health

Sarah Pfau, MPHConsultantNCCPHP

What is Surveillance?

What is Surveillance?

CDC: The ongoing systematic collection, analysis, and interpretation of health data, essential to the planning, implementation, and evaluation of public health practice, closely integrated with the timely dissemination to those who need to know.

-Physicians

-Laboratories

-STD clinics

-Community health clinics

County and state health departments and CDC who analyze data using statistical methods

Standardized data collection

-Physicians

-Laboratories

-STD clinics



-Public health officials

-Health directors

-Health policy officials


Dissemination to those who need to know


-Physicians

-Laboratories

-STD clinics




-Health directors


Change in public health practice (vaccination, reduction of risk factors, medical intervention, etc.)




Public health planning and intervention

-Physicians

-Laboratories

-STD clinics




-Health directors


Change in public health practice (vaccination, reduction of risk factors, medical intervention, etc.)




Public health planning and intervention

Public health evaluation

NNDSS & NETSS

• The National Notifiable Disease Surveillance System (NNDSS)

• Disease-specific epidemiologic information

• 60 nationally notifiable infectious diseases

• 10 non-notifiable infectious diseases

• The National Electronic Telecommunications System for Surveillance (NETSS)

Elements of Surveillance

• Mortality reporting – legally required• Morbidity reporting – legally required• Epidemic reporting• Timely reporting• Laboratory investigations• Individual case investigations• Epidemic field investigations• Analysis of data

Types of Surveillance

• Passive

• Active

• Syndromic

Passive Surveillance

Laboratories, physicians, or other health care providers regularly report cases of disease to the local or state health department based on a standard case definition of that particular disease.

Communicable Disease Reporting:Passive Surveillance

Hospital PhysicianLab

LHD

State

CDC

Public

VA Reportable Diseases

http://www.vdh.state.va.us/epi/list.asp

http://www.vdh.state.va.us/epi/list.asp

VA Epi-1 Reporting Form for Paper-based Surveillance

VA Communicable Disease Law

Communicable disease statutes are in Chapter 2 of Title 32.1 of the Code of Virginia.

http://www.vdh.state.va.us/epi/appendxb.pdf

These articles are incorporated into and referenced throughout the State Board of Health’s Regulations for Disease Reporting and Control

http://www.vdh.state.va.us/epi/regs.pdf

http://www.vdh.state.va.us/epi/appendxb.pdf

http://www.vdh.state.va.us/epi/regs.pdf

Active Surveillance

Local or state health departments initiate the collection of specific cases of disease from laboratories, physicians, or other health care providers.

Communicable Disease Reporting:Active Surveillance

Hospital PhysicianLab

LHD

State

CDC

• Outbreak investigations

• Other times when complete case ascertainment is desired (e.g., research study)

Active Surveillance Applications

Question & Answer Opportunity

Syndromic Surveillance

The ongoing, systematic collection, analysis, interpretation, and application of real-time indicators for disease that allow for detection before public health authorities would otherwise identify them.

What are “indicators of disease?”

“Indicators” are clinical signs that we can categorize into syndromes, but NOT a

specific diagnosis!

Example:

Cough + Sore throat + Fatigue + Fever = Influenza-Like Illness

Common Syndromesunder Surveillance

• Gastroenteritis

• Influenza like illness (ILI)

• Meningitis / Encephalitis

• Rash / Fever

• Botulinic• Hemorrhagic

Why Do Syndromic Surveillance?

• Early detection of clusters in naturally occurring outbreaks or a BT event– Minimizes mortality & morbidity

• Characterize outbreak– Magnitude, rate of spread, effectiveness of control

measures

• Quick investigation

• Detection of unexplained deaths

Syndromic vs. Traditional Surveillance

00.10.20.30.40.50.60.70.80.9

1

0 24 48 72 96 120 144 168

Incubation Period (Hours)

Dis

ease

Det

ectio

n

Gain of 2 days

Effective Treatment Period

Traditional DiseaseDetection

Phase IIAcute Illness

Phase IInitial Symptoms

Early Detection

Source: Johns Hopkins University / DoD Global Emerging Infections System

Limitations of Syndromic Surveillance

• Inadequate specificity: false alarms– Uses resources in investigation

• Inadequate sensitivity: failure to detect outbreaks/BT events– Outbreak is too small– Population disperses after exposure,

cluster not evident

Limitations of Syndromic Surveillance

• Costly

• Staff expertise required

• Formal evaluation of syndromic surveillance systems are incomplete

Surveillance Applications

Applications• Establish Public Health Priorities

• Aid in determining resource allocation

• Assess public health programs– Facilitate research

• Determine baseline for detection of epidemics

• Early detection of epidemics– Estimate magnitude of the problem– Determine geographical distribution

Establish Public Health Priorities:

• Frequency (incidence / prevalence, mortality, years of life lost)

• Severity (case fatality rate, hospitalization, disability)

• Cost (direct, indirect)

Resource AllocationTUBERCULOSIS: Reported cases per 100,000 population,

United States and U.S. territories, 2002

Source: http://www.cdc.gov/dphsi/annsum/index.htm

Assess Public HealthPrograms

Data Graphed by Race and Ethnicity

Gonorrhea: reported cases per 100,000 population,United States, 1987 - 2002

Source: http://www.cdc.gov/dphsi/annsum/index.htm Data Graphed by Gender

*For 120 cases, origin of patients was unknown.

TUBERCULOSISamong U.S.-born and foreign-born persons, by year, United States, 1990-2002

Determine Baseline Rates

Early Detection of Epidemics0

5010

015

020

0N

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Number of flu patients by monthBoston, MA

Surveillance Limitations

Limitations

• Uneven application of information technology – Paper-based versus Electronic

• Timeliness– Reporting time requirement– Reporting burden

• Completeness– Unreported cases– Incomplete reports

CDC

Varied communications methods and security - specific to each system- including paper forms, diskettes, e-mail, direct modem lines, etc.

Current Situation

MMWR Weekly TablesMMWR Annual

SummariesProgram Specific Reports and

Summaries

State Health Dept

TIMSSTD*MIS

HARS

HARS STD*MIS TIMS NETSS EIP Systems

NETSS

STD*MIS (Optional at the Clinic)

TIMS (Optional

at the Clinic)

PHLISEIP System

s*

PHLIS

HARS STD*MIS

TIMS NNDSS EIP Systems

PHLIS

* EIP Systems (ABC, UD, Foodnet)

Data Source

sPhysici

ans

Varied communications methods and security - specific to each system - including diskettes, e-mail, direct modem lines, etc.

Chart Review

Lab Repor

ts

Reporting by Paper

Form, Telephone

& Fax

Statistical Surveys for

Chronic Diseases,

Injuries and Other Public

Health Problems

City/County Health Department

Limitations: Multiple Categorical Systems

National Electronic Disease Surveillance System (NEDSS)

• NEDSS is not a surveillance system

• Electronically integrate existing surveillance systems for easy data collection, storage and access

• Security to meet confidentiality needs

Guest Lecturer:Virginia’s Surveillance

Practices and Challenges

Lesliann Helmus, MS

Surveillance Chief

Division of Surveillance and Investigation

Office of Epidemiology, VDH

Overview

• Challenges in conducting surveillance

• NEDSS – tool to improve surveillance

• Application – Hepatitis A example

Surveillance Challengesin Virginia

• Quality of the data

• Balancing priorities

• Discrepancies and perspectives

• Translating data into information

Quality of the data

“The Government is very keen on amassing statistics. They collect them, add them, raise them to the nth power; take the cube root and prepare wonderful diagrams. But you must never forget that everyone of these figures comes in the first instance from the village watchman who puts down what he damn well pleases.”

Sir Josiah Stamp (1896-1919) - Head of the Inland Revenue Department of the UK

Quality of the Data

• Completeness of case ascertainment

• Completeness and accuracy of case information

• Timeliness of reports

• Sentinel indicators

‘Tip of the iceberg’

Reporter

RegionalOffice

CentralOffice

District

Flow of Reports in Virginia

CDC

Central Office

District

Quality of the Data

• Completeness of case ascertainment

• Completeness and accuracy of case information

• Timeliness of reports

• Sentinel indicators

‘Tip of the iceberg’

Balancing Priorities

Year Reported

HCV+ Test Results*

Acute Hep C Cases

Acute Hep A Cases

2001 1,265 3 167

2002 1,365 15 163

2003 4,313 15 141

2004 10,725 21 145

*Numbers may be inflated due to duplicates

Discrepancies and Perspectives

• Clinical vs surveillance case definitions

• Cases ‘worked’ vs cases ‘counted’

• Place of exposure, residence, diagnosis

• Re-infection or duplicate report

• Stats by date of onset, diagnosis, report

Translating Data into Information

• Provides the basis for public health action

• Requires sound analysis and interpretation

• Extracts meaningful, actionable findings

• Requires clear presentation of complex issues

NEDSS

A Tool to Improve Surveillance

National Electronic Disease Surveillance System

• Centralized data system for disease surveillance in Virginia

• Person based system – links health events• Accessed through the VDH network• Ensures data confidentiality and integrity• Supports electronic data submissions• Will modify processes for managing reports

Benefits from NEDSS

• Faster recognition of health problems– Electronic transmission from large facilities

(provides better data, faster)– Simultaneous district/region/central office

access to the data

Benefits from NEDSS

• Greater consistency in data interpretation– Shared case status (cases definitions)– Shared dates– ‘As needed’ guidance and coaching– Shared updates– Shared reports

Benefits from NEDSS

• Shift in effort– Cases entered once– Trail for chronic cases– Processing of electronic transmissions– Ability to monitor reporters activity

Benefits from NEDSS

• Bigger picture– Earlier look at data across jurisdictions– Identification of people with co-infections– More effective analysis across diseases

Benefits from NEDSS

• Shared tools– High level tools with low level maintenance for

users– Shared expertise

Surveillance Application Example

Hepatitis A

Example – Hepatitis A

Source: Virginia Disease Control Manual

Reporting

• Initial report – Phone call – 24/7 availability of Health Dept– Would trigger follow-up with case

• Follow-up documentation– Clinical (‘morbidity’) report– Laboratory report

Enter Information into NEDSS

Key Information from Provider

Laboratory Report Information

Patient Interview:Risk Information

Look for Bigger Picture

• Sporadic case ?• Part of ongoing

outbreak ?• Beginning of new

outbreak ?

• Day care age?• Subgroup? • General community?

Surveillance Data Analysis:Line Lists

Surveillance Data Analysis:Cross-tabs

Age Group

Risk 0-4 5-19 20-64 65+

Foodservice 0 0 3 0

Daycare 1 0 0 0

No Risk 0 1 2 1

Hepatitis A Cases Reported in the Past Week

Surveillance Data Analysis:Time Trends

Confirm Case – Submit Notification

Statewide Review and Analysis

• Monthly data http://www.vdh.state.va.us/epi/Data/month04.asp

• Annual Data http://www.vdh.state.va.us/epi/Data/annual02.asp

• Virginia Epidemiology Bulletin http://www.vdh.state.va.us/epi/bulletin.asp

• See Your District Epidemiologist

http://www.vdh.state.va.us/epi/Data/month04.asp

http://www.vdh.state.va.us/epi/Data/annual02.asp

http://www.vdh.state.va.us/epi/bulletin.asp

Question & AnswerOpportunity

5 minute break

Federal Public Health Surveillance

CDC’s Role in Surveillance

• Support the states– Provide training and consultation in public

health surveillance– Distribute and oversee funding

• Receive, collate, analyze, and report data• Suggest changes to be considered in

public health surveillance activities• Report to the World Health Organization

as required and appropriate

TABLE II. Provisional cases of selected notifiable diseases, United States, weeks ending June 5, 2004, and May 31, 2003 (22nd week)

CDC Surveillance Data Reporting

Federal Data Sources

• Over 100 federal surveillance systems• Collect data on over 200 infectious and non-

infectious conditions such as:– Active Bacterial Core Surveillance (ABCs)– Foodborne Diseases Active Surveillance Network

(FoodNet)– National West Nile Virus Surveillance System

(ArboNet)– Viral Hepatitis Surveillance Program (VHSP)– Waterborne-Disease Outbreak Surveillance System– Influenza Sentinel Physicians Surveillance Network

Federal Surveillance Resources

• CDC Morbidity and Mortality Weekly Report (MMWR)

http://www.cdc.gov/mmwr

• CDC Office of Surveillance http://www.cdc.gov/ncidod/osr/index.htm

Council of State and Territorial Epidemiologists (CSTE)

http://www.cste.org

• Collaborates with CDC to recommend changes in surveillance, including what should be reported / published in MMWR

• Develops case definitions

• Develops reporting procedures

Example: ArboNet

• ArboNet is a cooperative surveillance system maintained by CDC and 57 state and local health departments for detecting and reporting the occurrence of domestic arboviruses.

ArboNet - Data

• Human – Encephalitis, meningitis, fever, viremic blood

donors, other

• Dead bird

• Equine

• Mosquito

• Sentinel animals (chicken, pigeon, horse)

• Other non-human mammals

ArboNet – Surveillance Issues

• “Real-time” reporting– Novel occurrence of West Nile virus– Web-based reporting (states)– Still relies on paper-based reporting (local)

• Incorporates ecologic data

• NEDSS compatible

• Duplicity of human case reporting

ArboNet - Diseases

• West Nile virus• St. Louis Encephalitis virus• Eastern Equine Encephalitis virus• Western Equine Encephalitis virus• California serogroup viruses (i.e., La Crosse)• Powassan Encephalitis virus• Japanese Encephalitis virus• Dengue virus

What is West Nile Virus?

• Transmitted to humans via bites from infected mosquitoes

• Infection usually asymptomatic; some people have fever, headache, rash, swollen lymph glands.

• No infections documented in the Western Hemisphere until 1999; then 46 U.S. states reported WNV activity in 2003!

Virginia Arboviruses

• VA Department of Healthhttp://www.vdh.virginia.gov/whc/external_whc/westnilevirus.asp

• VA Arbovirus Surveillance and Response Planhttp://www.vdh.virginia.gov/whc/external_whc/Avianplan2004.asp

• State Laboratory of Public Health (VA Department of General Services)

• VA Department of Agriculture and Consumer Services– Local Department of Agriculture Veterinary Laboratories

• VA Department of Game and Inland Fisheries

• U.S. Army Center for Health Promotion and Preventive Medicine

http://westnilemaps.usgs.gov/

Cumulative Dead Bird West Nile Virus Infections: 2004

http://westnilemaps.usgs.gov/

Cumulative Human West Nile Virus Cases: 2004

Cumulative Human West Nile Virus Cases: 2004

http://westnilemaps.usgs.gov

Video Clip:Public Health Grand Rounds

“Preparing for West Nile Virus: Will Your Community be Next?” (May 2001). [email protected]

Notice:• Surveillance lessons learned by public health officials • How the manifestation of the virus makes it easy to

involve the general public in surveillance efforts

• How quickly West Nile Virus has spread across the U.S. in only a few years

Example: Influenza

U.S. Influenza Surveillance

1. World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories

2. State and Territorial Epidemiologists’ Reports

3. 122 Cities Mortality Reporting System4. U.S. Influenza Sentinel Providers

Surveillance Network (voluntary)

U.S. Influenza Surveillance

Does. . .• Find out when and where

influenza is circulating • Determine what type of

influenza viruses are circulating

• Detect changes in the influenza viruses

• Track influenza-related illness

• Measure the impact influenza is having on deaths in the United States

Does Not. . .

Ascertain how many people have become ill with influenza during the influenza season

Influenza-like IllnessCase Definition

The Influenza-Like Illness case definition for CDC’s surveillance system is:

1. Fever of 100 degrees Fahrenheit or higher

2. AND cough OR sore throat.

CDC Sentinel Influenza Surveillance

http://www.cdc.gov/flu/weekly/

VA Influenza Surveillance

Goal: “. . .to detect outbreaks of influenza as early and quickly as possible in order to facilitate early public health intervention and to specify the organisms involved.”

1. Passive surveillance2. Laboratory surveillance3. Active sentinel component

Virginia Active Sentinel Surveillance

• Virginia Department of Health conducts active surveillance with physicians around the state

– Season is October - April

– 60 – 70 physicians represent medical practices in each of the state’s five health planning regions

• Primarily family practice or internal medicine

VA Influenza-like Illness Surveillance Activity

http://www.vdh.state.va.us/epi/flu.htm

Access VA and CDC Reports

Reports of Influenza Activity in the

Virginia Surveillance Program:

http://www.vdh.state.va.us/epi/flu.htm

CDC reports and charts containing national and regional data:

www.cdc.gov/ncidod/diseases/flu/weekly.htm

5 minute break

Guest Lecturer: Techniques for Analysis of

Surveillance Data

Sarah Pfau, MPH

Consultant, NCCPHP

Overview• Considerations when working with surveillance

data

• Descriptive Epidemiology

• Access surveillance data in Microsoft Excel or Access formats

• Access online census data

• Analyze surveillance data

Considerations

• Surveillance data primarily yield descriptive statistics

• Know the inherent strengths and weaknesses of a data set

• Examine data from the broadest to narrowest

Rely on Computers to:

• Generate Simple, Descriptive Statistics– Tables: frequencies, proportions, rates– Graphs: bar, line, pie– Maps: census tracts; counties; districts

• Aggregate or Stratify Rates– State versus county– Multiple weeks or months or years– Entire population versus age, gender, or race specific

Rely on Public Health Professionals to:

• Contact health care providers and laboratories to obtain missing data;

• Interpret laboratory tests;

• Make judgments about epidemiological linkages;

• Identify or correct mistakes in data entry; and

• Determine if epidemics are in progress.

Surveillance Data

Descriptive Epidemiology

Person, Place, and Time

Person: What are the patterns of a disease among different populations?

Place: What are the patterns of a disease in different geographic locations?

Time: What are the patterns of a disease when compared at different times (e.g., by month, year, decade) ?

5000

10000

15000

20000

25000

30000

1992

1994

1996

1998

2000

2002

# o

f c

as

es

US born

Foreign born

Overall

Tuberculosis Cases: United States 1992 - 2002

Source: http://www.cdc.gov/epo/dphsi/annsum/2002/02graphs.htm

Raw Numbers versus Rates

Ratio

A ratio is any [fraction] obtained by dividing one quantity by another; the numerator and denominator are distinct quantities, and neither is a subset of the other.

- Teutsch and Churchill (1994).

Rates, Proportions, and Percentages are all some form of a Ratio.

What Do Rates Do?

• Measures the frequency of an event over a period of time

• Includes a numerator (e.g., disease frequency for a period of time) and a denominator (e.g., population)

Why Use Rates?

Rates provide frequency measures within the context of the population.

Raw Surveillance Data

Total

Population

Crude

Rate X 104

City A 10 1,000 .01 100 per 10,000

City B 10 1,000,000 .00001 .1 per 10,000

Crude versus Specific Rates

Crude Rate: Rate calculated for the total population

Specific Rate: Rate calculated for a sub-set of the population (e.g., race, gender, age)

Rate Numerator:VA Reportable Disease

Surveillance Data

Office of Epidemiology, Virginia Department of Health

http://www.vdh.state.va.us/epi/survdata.asp

Call: (804) 864 – 8141Email: [email protected]

Rate Denominator:U.S. Census Data

1. http://www.census.gov2. Click on the “State & County Quick Facts” hyperlink

• Choose VA in the dropdown menu and click on GO

3. Click on the “Browse Data Sets for Virginia” hyperlink at the top of the Quick Facts data table

4. Click on the “Virginia Counties” hyperlink for ‘Population by Race and Hispanic or Latino Origin’

5. Open a new, blank file in Microsoft Excel6. Highlight table cells on the Census web page, click

CTRL + C to copy data, then paste into the same number of cells in the Excel spreadsheet

7. Name / save the Excel file in the Epi2000 folder on your c:\ drive

Import Data from Microsoft Excel or Access into

Epi Info

“Read / Import” Command

“Read / Import” Dialogue Window

Import files from alternativeSoftware programs

Import Restrictions forMicrosoft Excel Files

There can be no spaces in either the Excel file name or the column and row header cells, or sheet names within an Excel file. You can, however, have spaces in other file names in the directory path.

These three components of an Excel file cannot contain characters (e.g., #, @, !)

The Excel file cannot contain any duplicate field names.

The Excel file must be saved in the path: c:\Epi2000 folder – NOT the c:\Epi_Info folder that tends to operate as the default folder for Epi Info files.

Import Restrictions forMicrosoft Access Files

There can be no spaces in either the file name or the table or form names within an Access file. You can, however, have spaces in other file names in the directory path.

These file components cannot contain characters (e.g., #, @, !)

The Access file must be saved in the path: c:\Epi2000 OR c:\Epi_Info folder.

Online Epi Info Training

“Importing and Exporting Data Tables”

http://www.sph.unc.edu/nccphp/training/all_trainings/at_epi_info.htm

Analyze Surveillance Data

Sample Analyses

1. Time trend graph of NC data over ten years, by year for Salmonella cases

Raw data Rates

2. Maps of Salmonella rates by county: 2000 Raw Data versus Rates Choropleth

Graph Surveillance Data

Line Graph: Raw Data

Line Graph: Rate Data

Archived U.S. Census Population Estimates

http://www.census.gov/popest/archives/1990s/

– National– State– County

Estimates: present and past

Projections: future

Line Graph

Raw Data Rates

Generating a Line Graph:Considerations

• Use an x-axis scale to show a trend over time

• Select an interval size that contains enough detail for the purpose of the graph

• Label x- and y-axes

Map Surveillance Data

Epi Map Instruction

“Generating Maps”

http://www.sph.unc.edu/nccphp/training/all_trainings/at_epi_info.htm

Raw Data Map

North Carolina Salmonella Cases by County: 2002

Data source: NC Communicable Disease Data by county for 2000, General

Communicable Disease Control Branch, Epidemiology Section, Division of Public Health

Choropleth Map

North Carolina Salmonella Cases by County: 2002

Data source: NC Communicable Disease Data by county for 2000, General Communicable Disease Control Branch, Epidemiology Section, Division of Public Health

Choropleth Map

North Carolina Salmonella Rates by County: 2002

Rate numerators: NC Communicable Disease Data for 2000

Rate denominators: U.S. Census population data, by county, for 2000

Raw Data

Rates

Data Interpretation:Considerations

• Underreporting

• Inconsistent Case Definitions

• Has reporting protocol changed?

• Has the case definition changed?

• Have new providers or geographic regions entered the surveillance system?

• Has a new intervention (e.g., screening or vaccine) been introduced?

Online Surveillance Trainings

NC Center for Public Health Preparedness

http://www.sph.unc.edu/nccphp/training/training_list/t_surv.htm

Direct link to 13 surveillance trainings

Session SummarySurveillance is the ongoing systematic collection, analysis, and interpretation of health data, essential to the planning, implementation, and evaluation of public health practice, closely integrated with the timely dissemination to those who need to know.

There are three broad forms of surveillance: passive, active, and syndromic. Passive and active differ primarily in the way in which data are reported to local health departments from health care providers, but both document confirmed cases. Syndromic surveillance involves collecting and analyzing real-time indicators for disease in an effort to identify an outbreak earlier than a traditional surveillance system will; however, cases are not confirmed via one standardized, case definition.

Session Summary

Surveillance data have many applications, including: establishing public health priorities; aiding in determining resource allocation; assessing public health programs; determining baseline rates for detection of epidemics; and early detection of epidemics.

The uneven application or availability of technologies, combined with the reporting burden and decentralized system of paper-based reporting, are inherent limitations of surveillance. Furthermore, electronic and paper-based reporting are only reliable when reporting practices are standardized and public health professionals and practitioners are trained in surveillance protocol and public health laws.

Session Summary

Federal and state or local surveillance go hand-in-hand; they are the result of a collaborative, reciprocal pathway for data collection and reporting.

When analyzing and interpreting surveillance data, it is advisable to graph rates versus raw data. It is also advisable to investigate broad, total population rates prior to evaluating specific rates for population strata such as race or gender.

Session IV Slides

Following this program, please visit the Web site below to access and download a copy of today’s slides if you have not already done so:


Don’t Forget!

Please submit your site sign-in sheet and session evaluation forms to:

Suzi SilversteinDirector, Education and Training

Emergency Preparedness & Response Programs

FAX: (804) 225 - 3888

Next Session: May 5th

Final Session in this 5-part Series

“Epidemiology Specialties Applied”

• Disaster

• Environmental

• Forensic

References and Resources•Bonetti, M. et al (August 2003). Syndromic Surveillance PowerPoint Presentation. Harvard Center for Public Health Preparedness.

•CDC case definitions

http://www.cdc.gov/epo/dphsi/casedef/case_definitions.htm

•CDC infectious disease surveillance systems

http://www.cdc.gov/ncidod/osr/site/surv_resources/surv_sys.htm

•CDC Integrated project: National electronic diseases surveillance system

http://www.cdc.gov/od/hissb/act_int.htm

References and Resources

• CDC nationally notifiable infectious diseases http://www.cdc.gov/epo/dphsi/phs/infdis2004.htm

• CDC Notifiable diseases/deaths in selected cities weekly information. MMWR. June 4, 2004/53(21); 460-468 http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5321md.htm .

• CDC Division of Public Health Surveillance and Informatics, Epidemiology Program Officehttp://www.cdc.gov/epo/dphsi

• General Communicable Disease Control Branch, Epidemiology Section, Division of Public Health, NC Department of Health and Human Services. Reportable Communicable Diseases – North Carolina.

References and Resources• Klein, R. and Schoenborn, C. (January 2001). Age Adjustment Using the

2000 Projected U.S. Population. Healthy People 2010 Statistical Notes: No. 20. National Center for Health Statistics, Centers for Disease Control and Prevention.

• Last, J.M. (1988). A Dictionary of Epidemiology, Second Edition. New York: Oxford University Press.

• Teutsch, S. and Churchill, R. (1994). Principles and Practice of Public Health Surveillance. New York: Oxford University Press.

• U.S. Department of the Interior, U.S. Geological Survey (January 19, 2005). http://westnilemaps.usgs.gov/background.html

• Virginia Department of Health Web site: http://www.vdh.state.va.us

References and Resources

• NC Center for Public Health Preparedness Surveillance Trainings:http://www.sph.unc.edu/nccphp/training/training_list/t_surv.htm

“Surveillance”“Utilizing Infectious Disease Surveillance Data”“Acute Disease Surveillance and Outbreak

Investigation”“Syndromic Surveillance in North Carolina, 2003”“North Carolina Communicable Disease Law”“Introduction to Surveillance”“Communicable Disease Surveillance in North

Carolina”

public health information network (phin) series i is for epi epidemiology basics for...

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