using geographical information system tool in containing influenza pandemic threats republic of...
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Using Geographical Information System tool in containing influenza
pandemic threats
Republic of LebanonMinistry of Public Health
Epidemiological Surveillance Program
Nada Ghosn, MD
Human influenza
• Seasonal influenza: – Annual outbreaks due to minor changes in the
surface of the influenza viruses – Human have partial immunity due to previous
infections.
• Pandemic influenza: (الجائحة)– Global and worldwide severe epidemic – Due to major change – No human have partial of fully immunity
against infection because it is a completely new virus.
Latest Influenza pandemics
1918:
“Spanish Flu”
20-40 million deaths
A(H1N1)
1957:
“Asian Flu”
1-4 million deaths
A(H2N2)
1968:
“Hong Kong Flu”
1-4 million deaths
A(H3N2)
Credit: US National Museum of Health and Medicine
Next?
“XX Flu”
millions deaths
A(H5N1)?
Animal influenza
• Avian influenza– Highly Pathogenic Avian Influenza (HPAI)– Low Pathogenic Avian Influenza
• Outbreaks of new avian influenza – Increase the risk of a human pandemic– Through the merging of animal and human
influenza viruses.
Influenza virus H5N1
• The new H5N1 avian influenza is a potential candidate for pandemic influenza:
1. Can affect animals and birds on a large scale
2. Can affect humans and cause severe disease
3. But still can not be transmitted from human-to-human
How to control/prevent pandemic influenza?
1. Containment of potential human pandemics at the source
2. Containment of HPAI in animals at the source
Pandemic Influenza modeling:Time factor
Any delay will reduce the probability of eliminating large
epidemics in humans
• Delay of 4 days reduce the probability of eliminating a large epidemic of a new pandemic virus to:– <50% for a virus with
R0=>1.5– R0 quantifies the
transmissibility of pathogen
Source: Ferguson, Derek, Cummings, Cauchemaz, Fraser, Riley, Meeyai, Lamsiiriithaworn, Burke. Strategies for containing an emerging influenza pandemic in Southeast Asia. Nature. Vol. 437. 8 September 2005
Probability of eliminating a large epidemic using social and geographical targeting prophylaxis, varying with the delay (0-4 days) from case detection to prophylaxis for the 5-km radius policy
Containment pandemic influenza WHO plan:time factor
The success of any strategy for containing an emerging pandemic
virus is strictly TIME DEPENDENT
WHO pandemic influenza plan
1. The success of any strategy for containing an emerging pandemic virus is strictly TIME DEPENDENT.
2. Objectives of containment strategy– To stop, or at least to slow, the spread of pandemic
influenza at the source of its emergence in order to reduce global morbidity and mortality
Source: WHO pandemic influenza draft protocol for rapid response and containment. 30 May 2006
WHO pandemic influenza plan1. Recognition of the event:
– Epidemiological and virological signals– Steps of initial investigation
2. Verifying the event: – Risk assessment– Immediate control measures
3. Containing the event:– Decision to launch a containment operation– Phase 1 - standard measures to reduce transmission: case
management, infection control, antiviral treatment, intensified surveillance, contact tracing, monitoring contacts for signs of illness
– Phase 2 - exceptional measures: voluntary quarantine, social distancing, mass antiviral prophylaxis
Source: WHO pandemic influenza draft protocol for rapid response and containment. 30 May 2006
FAO Recommendations1. Early detection, and rapid response
2. The main measures to prevent, control and eradicate HPAI are:
• Effective disease surveillance for early detection and reporting
• Enhanced biosecurity of poultry farms
• Control of movement of birds and products
• Changes to industry practices to reduce risk
• Rapid, humane destruction of infected poultry and poultry at high risk of infection (stamping out)
• Disposal of carcasses and potentially infective material in a biosecure and environmentally manner
• Proper use of vaccine
Source: FAO - 2005
Containment factors: available information
Available information can reduce delay in conducting response
measures
Lebanon: Influenza H7N7 risk Tyr caza, March-April 2006
• MOA:– What is the area size?– What are the target farms?– What are the target birds
size?– …
• Collecting data was time consuming (>2 days) and has delayed the stamping out measures
Lebanon: Influenza H7N7 risk Tyr caza, March-April 2006
• MOI– What is the target area?
– What is the area targeted for quarantine?
– What is the perimeter?
– How many human resources are needed?
– …
• Municipality:– How many human
resources are needed?– …
• Short cut of human resources was observed and prolonged field activities
Lebanon: Influenza H7N7 risk Tyr caza, March-April 2006
• MOPH:– What are the exposed
persons targeted for health monitoring ad active surveillance? Professionals, farms, households…
– What are the health structures in place for case referral and case management?
– What are the needed resources?
– …
Lebanon: Influenza H7N7 risk Tyr caza, March-April 2006
How to avoid containment delay?
1. Be prepared
2. Visualize risky areas
3. Have centrally available information and maps to decide on strategy and needed resources
4. Save time and act rapidly
Avian Influenza Preparednessusing GIS tool
1. Preparedness tool
2. Visualization of risky areas
3. Decision tool
4. Save time
If Influenza A/H5N1 virus appears in Lebanon
• All response measures aim to:– Prevent the spread of the virus– Contain the virus at the source (focus)
If Influenza A/H5N1 virus appears in Lebanon
• Response measures include:1. Specify a 3km radius zone from the index case and
control its movements at entry and exit2. Control (destroy) all poultry in the security zone (3km
radius)3. Detect poultry cases in a 7km radius zone with enhanced
veterinarian surveillance4. Detect human cases in affected areas5. Prepare health structures to manage human cases6. Close community gathering places7. Rise public and professional awareness
1. Quarantine - Security and Surveillance zones:
Actor Questions Parameters
Q1 MI/FSI What are the limits of the security and surveillance zones?
Q2 MI/FSI What are the needed resources to quarantine the security zone?
Needed quarantine resources / km (Human, equipment, financial, information)
Q3 MI/FSI What are the suitable places for the entry/exit check points?
Criteria for suitable places for check points
Q4 All What are the needed resources at the entry/exit check points?
Needed resources / check point (Human, equipment/material, financial, information)
1. Quarantine - Security and Surveillance zones:algorithm
Buffer 3kmBuffered Zone
3km
Select Road-based
Security ZoneSecurity zone
IndexCase
Buffer 7kmBuffered Zone
7km
SelectRoads-based
Surveillance Zone
Roads
Surveillance zone
FSI Report:Needed
Quarantine resources
FSI Report:Suitable Entry/exit
check points
All Report:Needed
Resources at check points
Spatial map
Q1
Q1
Q2 Q3 Q4
Suitable places For checkpoints
Suitable check points
Actor Questions Parameters
Q1 MOA What are target farms and backyards for poultry stamping out? What are the target poultry population for stamping out?
Q2 MOA What are the needed resources for rapid and adequate stamping out?
Needed resources for adequate stamping out ( backyard, traditional & modern farm)
Q3 MOA What are the needed resources for farms disinfections?
Needed farms disinfections resources
Q4 MOA What are the suitable places for disposal carcasses and infective material without water contamination?
Criteria for suitable places for carcasses burial without water contamination
Q5 MOA/
MFWhat are the needed resources for farms compensation?
Compensation / poultry species, type and age
2. Destroy poultry in 3km radius zone
2. Destroy poultry in 3km radius zone: algorithm
FarmsDataBase
Select within Security Zone
Target Farms in security zone
MOA Report:Needed
stamping resources
MOA Report:Target
Farms in Security Zone
MOA Report:Compensation
estimations
Water resources
Land UseSuitability place
for burialSuitable Places
for carcasses burial
Spatial map
MOA Report:Needed
Disinfections resources
Security zone
Farms including slaughterhouses and poultry live markets
Q1
Q1
Q5
Q3Q2
Q4
Actor Questions Parameters
Q1 MOA What are the targeted farms and backyards for active surveillance?
Q2 MOA What are the targeted wild birds itinerary for active surveillance?
Q3 MOA What the needed resources for active surveillance, specimens collection and transportation?
Needed resources for active surveillance, specimens collection and transportation / surveillance point
3. Detect poultry cases in a 7km radius zone: questions
3. Detect poultry cases in a 7km radius zone: algorithm
FarmsDataBase
Proximity
Target Farms in surveillance zone
Select within Surveillance Zone
Target migratory Birds itinerary
MOA Report:Needed
surveillance resources
MOA Report:Target wild
birds surveillance
MOA Report:Target
Farms in Surveillance
zone
Migratory birds itinerary
Surveillance zone
Index Case
Farms including slaughterhouses and poultry live markets
Q3
Q2
Q1
Q1
Q2
Actor Questions Parameters
Q1 MOH What are targeted HEALTH STRUCTURES for enhanced and active surveillance?
Q3 MOH What are targeted FARMS for active human surveillance?
Q4 MOH What are targeted HOUSEHOLDS for active human surveillance?
Q5 MOH What the needed resources for active surveillance, specimens collection and transportation?
-Needed resources for active surveillance, health monitoring, specimens collection and transportation
-Needed resources for antiviral prophylaxis
4. Detect human cases in affected area:
4. Detect human cases in affected area: algorithm
Population
Proximity
MOH Report:Target Households
for active surveillance
Spatial Map(building blocks)
Health Structures
Surveillance zone
Security zone
Target Farms in security zone
MOH Report:Target Health Stru.
for active surveillance
Target poultry workers
Target households
Target Health structures for surveillance
MOH Report:Target Poultry workers for active surveillance
Q3
Q4
Q1
MOH Report:Needed
Surveillance resources
Q5
Q1
Q4
Q3
MOH Report:Needed
Anti-viral prophylaxisresources
Q5
Actor Questions Parameters
Q1 MOH What are targeted health structures for case referral?
Criteria for reference health structures
Q2 MOH What are targeted health structures for training on case management and infection control?
Criteria for training health structures
Q3 MOH What are needed resources for training on cases management and infection control?
Needed resources for training on cases management and infection control / site
Q4 MOH What are needed resources for protecting, monitoring and ensure prophylaxis for care providers?
Needed resources for protecting, monitoring and ensure prophylaxis / person
5. Prepare health structures to manage human cases:
5. Prepare health structures to manage human cases:algorithm
Population
Suitability & Proximity
MOH Report:Needed resources
for training on case management
and infection controlSpatial Map
(building blocks)
Health Structures
Surveillance zone
Security zone
MOH Report:Reference
Health structures
Reference Health structures
MOH Report:Reference patient transport service
Q1Q1
Q1
Q3
Patient transport services
Reference Transport services
Q1
Target health structures
for training
Q2
MOH Report:Needed resources for
protecting care providers and antiviral prophylaxis
Q4
Actor Questions
Q1 All What are targeted community gathering places for closure?
Q2 All What are needed resources to ensure closure of targeted community gathering places?
6. Close community gathering places:
6. Close community gathering places: algorithm
Target Schools for closure
Proximity
Target Common places for closure
Report:Target
Common places
Report:Needed resources
to ensure Closure
implementation
Report:Target
schools
Schools
Community gathering
places
Spatial Map(building blocks)
Surveillance zone
Security zone