What’s New in Surveillance

Dona Schneider, PhD, MPH

Surveillance 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 feedback of these data to those who need to know. Centers for Disease Control

Examples: Morbidity and Mortality Weekly Report (MMWR)Disease Registries

Surveillance for communicable diseases remains important…

The world population is highly mobile

International travel and troop movements increase the risk of communicable disease transmission

Migration for war and famine, and voluntary immigration increase communicable disease risk

Naturally occurring disease is not our only threat

Types of Surveillance

Passive Inexpensive, provider-initiated Good for monitoring large numbers of typical health events Under-reporting is a problem

Active More expensive, Health Department-initiated Good for detecting small numbers of unusual health events

Enhanced Rapid reporting and communication between surveillance agencies

and stakeholders Best for detecting outbreaks and potentially severe public health

problems

New and complex disease entities must also be monitored…

New syndromes may emerge that present in an atypical manner

Syndromic surveillance uses health-related data that precede diagnosis and signal a sufficient probability of a case or an outbreak to warrant further public health response

Day 1- feels fine Day 2- headaches, fever - buys Tylenol Day 3- develops cough - calls nurse hotline Day 4- Sees private doctor – dx with “flu” Day 5- Worsens - calls ambulance seen in ED Day 6- Admitted - “pneumonia” Day 7- Critically ill - ICU Day 8- Expires - “respiratory failure” Case enters surveillance system through an EDC

Example of Passive Surveillance

Day 1- feels fine Day 2- headaches, fever - buys Tylenol Day 3- develops cough - calls nurse hotline Day 4- Sees private doctor - dx “flu” Day 5- Worsens - calls ambulance - seen in ED Day 6- Admitted - “pneumonia” Day 7- Critically ill - ICU Day 8- Expires - “respiratory failure” Case is under immediate investigation by the LHD

because of the pre-diagnostic information gathered

Pharmaceutical Sales

Nurse’s Hotline

Managed Care Org

Ambulance Dispatch (EMS)

ED Logs

Absenteeism records

Example of Syndromic Surveillance

We also watch for sentinel events…

Sentinel surveillance identifies preventable disease, disability, or deaths that warn that known methods of prevention, treatment or safety need to be improved

Sentinel events may have catastrophic outcomes – they may indicate the “tip of the iceberg”

Sentinel Surveillance

Monitors Sites Events Providers Vectors/animals

SENTINEL EVENT Nov 12, 2001 - 9:17 am Flight AA 587 Crashes in Rockaways

7-Zip Surveillance showed:

27 Obs / 10 Exp Resp Emergencies p<0.001

31 Obs / 16 Exp Hospital Events p<0.05

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Rockaways

Rest of City

Investigation

Key Questions True increase or natural variability? Bioterrorism or self-limited illness?

Available Methods Response team assigned Response team “Drills down” Query clinicians / laboratories Chart reviews Patient follow-up Increased diagnostic testing

Investigation

Chart review in one hospital (9 cases) Smoke Inhalation (1 case) Atypical Chest Pain / Anxious (2 cases) Shortness of Breath - Psychiatric (1 case) Asthma Exacerbation (3 cases) URI/LRI (2 cases)

Checked same-day logs at 2 hospitals Increase not sustained

Surveillance can…

Estimate the magnitude of a problem Determine geographic distribution of illness Detect epidemics/outbreaks Generate hypotheses, stimulate research Evaluate control measures Monitor changes in infectious agents Detect changes in health practices

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Data Sources

Notifiable diseases Laboratory specimens Vital records Sentinel surveillance Registries and surveys Administrative data systems Other data sources

Reported Cases of Food borne Botulism, United States, 1981-2001

*Data from annual survey of State Epidemiologists and Directors of State Public Health Laboratories.

Source: CDC. Summary of notifiable diseases. 2001.

Cases of MeaslesUnited States, 1966-2001

Source: CDC. Summary of notifiable diseases. 2001.

Blood Lead Measurements 1975-1981

1975 1976 1977 1978 1979 1980 198130

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Year

Predicted blood lead

Gasoline lead

Observed blood lead

Source: Pirkle et al JAMA 272:284-91, 1994

Lead used in gasoline(thousan

dsof tons)

Mean bloodlead

levels g/dl

Reported Salmonella Isolates,* United States, 1976-2001

*Data from Public Health Laboratory Information System (PHLIS).

Source: CDC. Summary of notifiable diseases. 2001.

National Notifiable Diseases Surveillance System (NNDSS) – produces the data in the

MMWR

The reportable diseases list is revised periodically by the CSTE/CDC

States report diseases to the CDC voluntarily Reporting is mandated at the state level All states report the internationally quarantinable

diseases (i.e., cholera, plague, SARS, smallpox and yellow fever) in compliance with WHO International Health Regulations and a varied list of other diseases

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        

In New Jersey

Reporting mandated by state law/regulation Health care providers, laboratories report to the

LHD (county) LHD submits reports to the State Reports transmitted by State to CDC primarily

through National Electronic Telecommunications System for Surveillance (NETSS)

Other NCHS Data Systems for Surveillance

Vital Statistics National Infant Mortality Surveillance (NIMS) Linked:

• birth records• death records

SENSOR

Sentinel

Event

Notification

System for

Occupational

Risks

Recent Occupational Monitoring Efforts for Sentinel Events Include…

Biodetection Systems (BDS) in NJ post offices to detect anthrax and soon, ricin

Biowatch, an air monitoring system in New York City and 30 other cities

Weekly Communicable Disease Reporting System (CDRS) Alerts

Comparison of current 4-week reporting period to previous reporting periods; generated at NJDHSS every Monday by disease by county

Increase over baseline (3 SD) triggers an alert for further investigation

Limitation: timeliness of reporting into CDRS

County DiseaseCum

ReportsBaseline4-wk Av SD

Last 4-wk

Period Flag

Amebiasis (Entamoeba histolytica) 211 5.5 4.6 8  

√  Campylobacteriosis (Campylobacter

spp)1,296 40.6 17.6 28  

√  Creutzfeld-Jakob disease 21 1.0 0.0 1  

  Cryptosporidiosis (Cryptosporidium spp.)

52 1.8 0.8 1  

  Encephalitis, West Nile 42 5.6 4.3 2  

√  Enterohemorrhagic E. coli O157:H7 171 7.1 4.5 3  

√  Giardiasis (Giardia lamblia) 1,427 51.9 9.9 21

√  Haemophilus influenzae - invasive

disease167 4.3 1.9 1  

County ZIP Category Sale

BaseMeanDate 1

Sales inDate 1

BaseMeanDate 2

Sales inDate 2

BaseMeanDate 3

Sales inDate 3

Diarrhea N 3.9 8 (03/11/03) 3.6 4 (03/12/03) 5.3 11 (03/13/03)

Antifever N 12.4 6 (03/11/03) 11.4 9 (03/12/03) 10.0 20 (03/13/03)

Diarrhea N 2.7 3 (03/11/03) 3.5 3 (03/12/03) 3.6 8 (03/13/03)

Cough/Cold N 35.7 30 (03/10/03) 37.8 30 (03/11/03) 18.6 53 (03/12/03)

Cough/Cold N 44.0 42 (03/10/03) 52.7 45 (03/11/03) 27.0 72 (03/12/03)

Cough/Cold N 192.6 178 (03/11/03) 193.3 181 (03/12/03) 167.3 191 (03/13/03)

Hydrocort-isones

N 2.5 1 (03/10/03) 2.1 2 (03/11/03) 1.7 6 (03/12/03)

Cough N 11.3 14 (03/11/03) 7.7 13 (03/12/03) 11.3 15 (03/13/03)

Antifever Y 9.3 9 (03/11/03) 5.1 4 (03/12/03) 3.9 13 (03/13/03)

Antifever Y 8.8 11 (03/11/03) 7.7 8 (03/12/03) 5.7 20 (03/13/03)

New Jersey Real Time Outbreak and Disease Surveillance (RODS) OTC Surveillance

Reports Through March 15, 2003

Cipro and Doxycycline Prescriptions

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7/1/2001 7/29/2001 8/26/2001 9/23/2001 10/21/2001 11/18/2001 12/16/2001 1/13/2002

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Cipro Doxycycline

9/11

First anthrax case reported, 10/4/01.

CDC recommends doxycyline 10/28/01.

Tobacco Cessation Aids Sold at a Large Pharmacy Chain

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Week Ending

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its

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,000

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pti

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s$0.39

increase in State tax

$1.42 increase in City

tax

National Electronic Disease Surveillance System (NEDSS)

Will replace NETSS, HIV/AIDS, TB, STD, vaccine-preventable and infectious disease reporting systems

Goal is to standardize health reporting and link laboratory, hospital and managed care data

Enhanced and Syndromic Surveillance

Costs Implementation costs are modest Operational costs = time of public health staff,

investigations

Benefits Possibily huge if early detection results Strengthens traditional surveillance Sets high standards for all data collection agencies

Good surveillance does not necessarily ensure

the making of right decisions, but it reduces the

chances of wrong ones.

Alexander D. LangmuirNEJM 1963;268:182-191

Free Resources

World Health Organization

DISMOD Software

Centers for Disease Control

Epi Info