SURVEILLANCE OF INFECTIOUS DISEASE

Question 1

PH SURVEILLANEC?

Answer 1

• CLOSE OBSERVATION
• OBSERVING ACTIVITY THAT INFORMS US ABOUT THE HEALTH OF THE POPULATION
  DEFINITION: SYSTEMATIC ONGOING COLLECTION, ANALYSIS AND INTERPRETATION OF DATA AND TIMELY DISSEMINATION TO THOSE WHO NEED TO KNOW SO THAT ACTION CAN BE TAKEN
  ‘INFORATION FOR ACTION’!!!!!!!!!!!!!!!

Question 2

TRUE OR FALSE: WE CAN MONITOR BOTH INFECTIOUS AND NON INFECTIOUS DISEASE?

Answer 2

TRUE

Question 3

4 MAIN CAUSES OF INFECTIOUS DISEASES?

Answer 3

BACTERIA, VIRUSES, FUNGI, PARASITE

Question 4

WHY IS SURVEILLNCE OF DISEASE NEEDED?

Answer 4

‘INFORMATION FOR ACTION’ —> PURPOSE OF SURVEILLANCE IS TO GUIDE RESPONSE

• UNDERSTANDING BURDEN OF DISEASE
• DETECT DISEASE WHERE AND WHEN IT HAPPENS
• TARGETING INTERVENTIONS, E.G. VCCINES
• TARGETING POPULATIONS/REGIONS
• STOPPING DISEASE BEFORE IT SPREADS
• REDUCING INEQUALITIE
• IMPROVING THE HEALTH OF THE POPULATION
• IDENTIFYING CLUSTERS AND TARGETING CAUSES

Question 5

KEY ASPECTS OF PH SURVEILLANEC?

Answer 5

ONGOING: ROUTINE OVER SAME PERIOD, PERHAPS INDEFINITE (NOT SHORT-LIVED!!)
SYSTEMATIC: ENSURE ALL NECESSARY INFO COLLECTED, ENSURE SAME DEFINITIONS ARE EMPLOYED, ENSURE DATA COLLECTED IN THE SAME FORMAT
COLLATION: FROM MULTIPLE SAMPLE POINTS
ANALYSIS: USING APPROPRIATE METHODS
INTERPRETATION: BASED ON UNDERSTANDING OF OBJECT OF SURVEILLANCE
DISSEMINATION: TIMELY INFO TO THOSE WHO NEED TO KNOW

Question 6

AIMS OF SURVEILLANCE?

Answer 6

1) ASSESS PUBLIC HEALTH STATUS (MEASURE BURDEN OF DISEASE, TRENDS, AND INFORMSERVICE DLEIVERY, IDENTIFY EMERGING PROBLEMS, GUIDE PLANNING AND IMPLEMENTATION OF PROGRAMS TO PREVENT AND CONTROL DISEASE)
2) EVALUATE PUBLIC HEALTH PROGRAMS (EVALUATE EXISTING POLICY AND INTERVENTIONS)
3) INFORM RESEARCH (GENERATE HYPOTHESES)
4) DEFINE PUBLIC HEALTH PRIORITIES (IN CONJUNCTION WITH OTHER SOURCES OF EVIDENCE)

Question 7

SURVEILLANCE CYCLE?

Answer 7

1) DATA COLLECTION AND COLLATION ——————>
2) ANALYSIS AND INTERPRETATION ——————–>
3) DISSEMINATION OF INFO ————————> (1)

Question 8

EXAMPLES OF TYPES OF SURVEILLANCE SYSTEMS?

Answer 8

• INDICATOR (COMMON, INDICATORS CHOSEN, E.G. HOSPITAL ADMISSIONS FOR FLU)
• EVENT BASED (E.G. SPECIFIC OUTBREAKS)
• SYNDROMIC (COLLECTING PRESENTATION OF SPECIFIC SYMPTOMS, E.G. COUGH)
• PASSIVE (DATA SENT IN AS A PART OF E.G. CERTAIN LEGAL FRAMEWORKS, LIKE MENINGITIS CASES PHONED FROM A GP)
• ACTIVE (LOOKING FOR CASES BY E.G. PHONING GPS)
• SENTINEL ( NO FULL POPULATION COVERAGE BUT REPRESENTATIVE POPULATION AVAILABLE)
• COMPREHENSIVE (100% POPULATION COVERAGE)
• PARTICIPATORY (PATIENTS INVITED TO PARTTAKE IN THINGS LIKE SURVEYS)
  ………..

Question 9

DISEASE PYRAMID?

Answer 9

REPRESENTS THE NUMBERS OF PEOPLE WITH A PARTICULAR DISEASE AND THE SEVERITY OF PRESENTATION = WHERE THEY MIGHT PRESENT IN THE HEALTHCARE SYSTEM
IN ORDER FROM ‘MOST PEOPLE, LEAST SEVERE’ TO ‘LEAST PEOPLE, MOST SEVERE’:
- INFECTED (ASYMPTOMATIC)
- COMMUNITY (SELF-TREAT, MIGHT VISIT A E.G. PHARAMACY)
- COMMUNITY (NHS 111, CALL IN TO GET HEALTH ADVICE)
- COMMUNITY (GP)
- EMERGENCY DEPARTMENT
- HOSPITALISED
- DEAD

Question 10

SURVEILLANCE DATA SOURCES?

Answer 10

• NHS 111 CALLS
• GP CONSULTATIONS
• PHYSICIAN DIAGNOSES
• HOSPITAL ADMISSIONS
• ICU/ER ADMISSIONS
• MORTALITY
• LAB REPORTS
• SOCIAL MEDIA, GOOGLE SEARCHES
• SURVEYS
• ‘SELF-TESTING’ (E.G. LFT FOR OVID)
• SYMPTOMS REPORTING
• MEDICINE SALES
• SCHOOL ABSCENCE
  ETC.

Question 11

‘THE SURVEILLANCE ICEBERG’

Answer 11

• SURVEILLANCE DOESN’T CAPTURE EVERYONE
• DATA SOURCES FOR SURVEILLANCE USUALLY ENCOMPASS CASES THAT ARE JUST ‘THE TIP OF THE ICEBERG’
• A LOT OF EXPOSED, INFECTED AND EVEN SYMPTOMATIC INDIVIDUALS DO NOT ENGAGE WITH THE HEALTHCARE SYSTEM
• SURVEILLANCE NUMBERS PRACTICALLY ALWAYS UNDERESTIMATE THE REAL SEVERITY OF A SITUATION

Question 12

WHEN TO UNDERTAKE SURVEILLANCE/SET UP A SURVEILLANCE SYSTEM?

Answer 12

• POTENTIAL FOR SIGNIFICANT MORTALITY OR MORBIDITY FROM THE SURVEILLANCE TARGET
  &
• POENTIAL FOR PH INTERVENTION USING INFO DERIVED FROM THE SURVEILLANCE SYSTEM
  &
• SURVEILLANCE IS FEASIBLE (AND NOT ALREADY OPERATING)

Question 13

AIM OF ANALYIS IN CONTEXT OF PH SURVEILLANCE?

Answer 13

PROCESS RAW DATA INTO INFO THAT CAN BE USED FOR DECISION MAKING (GENERATION OF HYPOTHESES, DETECTION OF OUTBREAKS, ASSURANCE OF LACK OF IMPACT…)

Question 14

SURVEILLANCE IMPROVES OUTCOMES FOR INDIVIDUALS OR POPULATIONS MORE?

Answer 14

POPULATIONS

Question 15

PH SURVEILLANCE: ANALYSIS OF DATA –> STARTING STEPS?

Answer 15

• CHARACTERISE PATTERN OF DISEASE REPORTS BY PERSON, PLACE AND TIME
• COMPARE WITH SOME ‘EXPECTED VALUE’

Question 16

HOW CAN ‘CASES’ IN EPIDEMIOLOGY BE GRADED?

Answer 16

• SUSPECTE
• PROBABLE
• CONFIRMED

Question 17

COMMON ERRORS IN ANALYSIS OF PUBLIC HEALTH SURVEILLANCE DATA?

Answer 17

PERSON: FAILURE TO TAKE INOT ACCOUNT POPULATION STRUCTURES (E.G. POPULATION DENSITY OR AGE/SEX STRUCTURE)
PLACE: MISCLASSIFICATION IN TERMS OF PLACE OF REPORTING/PLACE OF RESIDENCE
TIME: MISCLASSIFICATION IN TERMS OF DATE OF ONSET, DATE OF DIAGNOSIS, DATE OF REPORTING OR SPECIMEN DAT
OTHER:
- FAILURE TO TAKE STEP BY STEP APPROACH (CHANGE ONLY ONE CRITERION, LIKE TIME PLACE OR PERSON) AND ONLY WHEN THIS IS UNDERSTOOD, CHANGE MORE COMPLEX PARAMETERS
- FAILURE TO PRODUCE APPROPRIATE RECOMMENDATIONS FOLLOWING ANALYSIS

Question 18

HOW SHOULD PH SURVEILLANCE DATA BE INTERPRETED IF THERE IS AN APPARENT INCREASE IN CASES?

Answer 18

• ALWAYS TREAT AN INCREASE AS REAL UNTIL PROVEN OTHERWISE
• HOWEVER, NOT ALL APPARENT INCREASES IN DISEASE OCCURENCE REPRESENT TRUE INCREASES: CONSIDER POTENTIAL SOURCES OF ERROR (CHANGES IN TESTING, DELAYS IN REPORTING, IMPACT OF MEDIA ON REPORTING ETC)
• CONSIDER RANDOM CHANCE
  (REDUCED NUMBERS OF PATIENT PRESENTATION IS NOT!!! AN ERROR)
• ALWAYS TRIANGULATE WITH OTHER SOURCES (MORE=BETTER)

Question 19

METHODS OF DISSEMINATING/SPREADING PH INFO ACQUIRED THROUGH SURVEILLANCE SYSTEMS?

Answer 19

• ROUTINE REPORTS
• ROUTINE EPIDEMIOLOGICAL SUMMARIES
• WEB-BASED DATASETS
• RESEARCH ARTICLES
• SPECIAL REPORTS, GUIDELINES, BRIEFINGS
• ONLINE DASHBORDS

Question 20

CYCLE OF PLANNING A SURVEILLANCE SYSTEM?

Answer 20

• AGREE CLEAR OBJECTIVES
• DEVELOP CASE DEFINITIONS
• DETERMINE DATA SOURCE/COLLECTION MECHANISM
• FIELD TEST METHODS
• DEVELOP AND TEST ANALYTICAL APPROACH
• DEVLOP AND SGREE DISSEMINATION MECHANISM
• ENSURE USE OF ANALYSIS AND INTERPRETATION

Question 21

ETHICS/GOVERNENCE ASSOCIATED WITH PH SURVEILLANCE?

Answer 21

• DATA PROVIDER: APPROVL/SUPPORT
• ORGANISATION
• PATIENT INFO
• PATIENT OPT OUT
• DATA SECURITY
• REPORTING (SOME ANONYMISED)
• GENERAL DATA PROTECION REGULTION

Question 22

KEY CRITERIA USED TO EVALUATE A PH SURVEILLANCE SYSTEM?

Answer 22

• SIMPLICITY
• FLEXIBILITY
• DATA QUALITY
• ACCEPTABILITY
• SENSITIVITY
• PREDICITIVE VALUE POSITIVE
• REPRESENTATIVENESS
• TIMELINESS
• STABILITY