Event-Based
Surveillance and
Response
Event-based Surveillance is the organized and
rapid capture of information about events that
have the potential to be a public health risk.
Objectives of ESR:
1. To capture all types of health events with
potential public health risk including rare and
new events
2. To immediately assess and respond to all
captured health events
3. To immediately disseminate available
information regarding ongoing health
events to relevant or concerned agencies
Framework of ESR
Event-based Surveillance Indicator-based Surveillance
Information Health Care
Sources Events Data
Facilities
Capture Collect
Media
Filter Analyse Department of
LGUs
Verify Interpret Health and
NGOs
General Public concerned agencies
Signal
BFAR
BAI Assess Disseminate Concerned other
BOQ gov’t agencies
Public Health Alert
RITM
HEMB Concerned LGUs
Investigate
Other stakeholders
Control Measures
WHO-IHR
Types of Events:
A.Diseases in human
1. Epidemic prone
2. Food-borne diseases
3. Diseases with limited treatment
4. Diseases with consequence with trade or
travel
5. Related to International release of biological or
chemical agents
6. Changes in resistance profiles
7. Changes of trends in person to person transmission
B. Potential exposure for human
1. Accidental and deliberate outbreaks
2. Toxic chemical accidents
3. Radio-nuclear accidents
4. Environmental disasters
5. Zoonotic diseases with potential harm for
humans
Core Processes of ESR:
I. Capture
II. Filter
III. Verification
IV. Assessment
V. Response
VI. Feedback
CAPTURE
FILTER VERIFICATION
ASSESSMENT
RESPONSE
FEEDBACK
I. Capture
Types of Capture
A.Active – gathering of health events
done by the ESR Staff through media
B.Passive – health events reported by the
media people, health facilities (DOH),
partner agencies and local government
units through email, fax, phone calls or
text messages.
Examples of Active capturing of Health Events
II. Filter
It is the process of reviewing which health
events should be discarded or warrants
further investigation.
Criteria for Filtering a True Health Event
Unknown illness/unusual event
High mortality or morbidity
International disease spread
Interference with travel or trade
Disease for elimination/eradication
Suspected, accidental or deliberate
biological/chemical threats
III. Verification
It is a process which health events can
be substantiated from true multiple
sources of information
It involves getting more information
about the details of the event as to
time, place and person.
IV. Assessment
1. Public Health Event of Local Concern (PHELC)
2. Public Health Event of Regional Concern (PHERC)
3. Public Health Event of National Concern (PHENC)
4. Public Health Emergency of International Concern
(PHEIC)
Criteria for Assessment
1. Public Health Impact
• Cases and deaths
• Pathogens and population involve
• Agent, vehicle or route of transmission
• Pathogens eliminated or eradicated
• Risk for international spread
2. Need for assistance
• Technical expertise
• Laboratory diagnostics
• Enhanced surveillance
3. Response strategy requirements
• Technical expert for outbreak
investigation, prevention and control
Public Health Event of Local Concern (PHELC)
Event is confined to specific geographical area
(municipality, province) Local unit has the
capacity and resources to respond
Event involves diseases with existing
guidelines for control measures
Event does not require extensive laboratory
examination for diagnosis
V. Response
A process where actions and
decisions are carried out immediately
after assessment.
Response activities may vary
according to the level and capacity of
the agencies and institutions
involved.
Local ESUs response activities
Verification
Outbreak investigation
Implement Control measures
Referral for laboratory and
technical support
Referral for further evaluation
or operational research
VI. Feedback
A process where a written report
of a health event is disseminated
to stakeholders.
Practice: Filtering a True Health Event
1. 4 persons admitted on May 1, 3, 4 and 5, 2017 from Barangay
San Nicolas, Magsaysay with symptoms that fit case
definition of meningococcal disease (admitting diagnosis: T/C
meningococcemia)
2.A minority died after being bitten by a snake while working in
his farm at Brgy. Monteclaro, San Jose
3.30 cases of AGE both admitted and OPD from Barangay
Santo Nino, Rizal in the last 2 weeks
4. A family of 5 was rushed into the hospital with
symptoms of continuous vomiting, headache and
body malaise. History involves alleged consumption
of poisonous mushroom.
5. A Patient died with symptoms of fever and cough
and later on diagnosed with Pneumonia. (Person is an
OFW from Saudi Arabia, flight to Philippines
reported: with passenger positive for MERS-COV)
6. Unknown cause of mortality of 3 minority
from Pag-asa, Sablayan
7. 1 person committed suicide by hanging,
admitted and was out of life threatening
condition
8. A case of dog bite, person is essentially well,
no symptoms, with anti-rabies immunization
