Spatial analysis to identify risk areas

of an important animal disease

(Highly Pathogenic Avian Influenza)

and to evaluate current strategy

in health surveillance in Europe

Irene Iglesias iglesias@inia.esMarta MartínezAna de la TorreMª Jesús MuñozJM Sánchez-Vizcaíno

(CISA-INIA UCM)

Animal diseases control

Affected animals and.....:

Trade in animal products

Vaccines

Control of disease: loss of livestock, compensation, health costs

Public confidence

......

Animal diseases control

Zoonotics

Tuberculosis

Salmonella

Avian Influenza

…

Animal diseases control

Affected countries: stop spread

Free countries: early detection

Preventivesurveillance

Animal diseases control: SURVEILLANCE

random samplingsystem

Preventivesurveillance

Animal diseases control: SURVEILLANCE

massive expansionavian influenza

TARGETTARGET

SURVEILLANCESURVEILLANCE

RiskRiskassessmentassessment

random samplingsystem

assessmentassessment

EC 2010/367/EU

Preventivesurveillance

Animal diseases control: SURVEILLANCE

TARGETTARGET

SURVEILLANCESURVEILLANCE

RiskRiskassessmentassessmentassessmentassessment

Spatial analysis:

Exploring data

Risk assessment

Modelling diseases

G.I.S.

Preventivesurveillance

• Affected countries (2004-2010)

HighlyPathogenicAvianInfluenza

( SubtypeH5N1)

has killed ≈ 400 million domestic birds

Cbc.caartsandopinion.com new.dpi.vic.gov.auartsandopinion.com new.dpi.vic.gov.au

Social alarm :332 fatal human cases

High economic losses ≈ ($20 billion)

HighlyPathogenicAvianInfluenza

( SubtypeH5N1)

The main difference...

• has killed ≈ 400 million domestic birds

Natural reservoir����Affected birds

Has killed ≈ 15.000 waterbirds

Highly Pathogenic Avian Influenza

( Subtype H5N1)

In the last 4 years...

HighlyPathogenicAvianInfluenza

( SubtypeH5N1)

•Tradepoultry

•MigrationrouteswaterbirdsSpread in Europe

Spatial analysis to identify risk areas of Highly Pathogenic Avian Influenza and to evaluate current strategy of

health surveillance in Europehealth surveillance in Europe

Visualization

Spatial analysis process: Modelling

Data base

Exploration

Modelling

StatisticsUseful & efficient decision-

making tool for different

epidemiological situations

in animal health

Data base

Avian InfluenzaCases in domestic birds

Avian InfluenzaCases in wildbirds Modelling with G.I.S.

Domestic birdsCensus/farms/location

WildbirdsCensus/location

Cases in domestic birds Cases in wildbirds Modelling with G.I.S.

WHERE should we do an efficient surveillance of

Avian Influenza in wildbirds???

TARGETTARGET

SURVEILLANCESURVEILLANCESURVEILLANCESURVEILLANCE

Spatial analysis to identify risk areas of Highly Pathogenic Avian Influenzaof Highly Pathogenic Avian Influenza

in waterbirds

1. Infected water represents a recognized mechanism for the virus transmission

within waterbird populations

2. Wetlands concentrate many waterbirds species → Increasing the risk of infection

Importance of wetlands in spread of Avian _Influenza

Modelizationof ENVIRONMENTAL RISK FACTOR for European WETLANDS

Distances Ramsar European Wetlands (Wetlands.org)

Avian influenza cases in wild birds (06-09)

Infected wetlands!

“Positive wetland”Wildbirds outbreaks

( Ramsar wetland

Europe

WetlandsOutbreaksInfected wetlands

16Km

• Analysis tools• Spatial analysis

Study wetlands characteristics

Modelizationof ENVIRONMENTAL RISK FACTOR for European WETLANDS

Water: Salinity, permanence

organic or mineral soil, ....

Land Use: Forestry, hunting,

Agriculture, aquaculture,...

Biological: Wintering birds area,

species, important area for fish..Logistic regression

analysis

• Analysis tools• Spatial analysis

• Logistic regressionIdentification of risk factors

•Mixosaline water

•Forestry around wetland

•Wintering waterbird area

analysis

!

“Infected wetlands”

Waterbird cases

( Ramsar wetland

Europa

Risk map for ocurrence of Avian Influenza in wildbirds

Logistic regression model

2009GERMANY

ROMANIA 2010

BULGARIA 2010

• Spatial analysis:Kernel

USEFULINFORMATION

ON TARGET SURVEILLANCE

Aplication of the model a national level: Spain

Increased Nº wetlands

•Wetlands Ramsar+Spanish Wetlands

(NationalDatabase)

Interpolate data model : IDW

(Inverse Distance Weighting)Provinces

Risk of modelHigh: 0.83

Logistic regression model

Adjust risk by climatic data

( temperature analysis)

• Geostatistical analysis:IDW

Low:0.10

Survival curve

Survival by temperature analysis

Wildbird case in Pais Vasco (2006)

Salburua

MCDMulticriteria

Decision:

Logistic regression model

Wildbird case in Pais Vasco (2006)

Farm affected

contact with wildbirds

(2009)

Almoguera

• Spatial analysis:Math

HighHigh

LowLow

RiskRisk valuesvalues ((OctoberOctober))

ProvincesProvinces

EuropeEurope

Risk of ocurrence of Avian Influenza in wildbirds

2006 High Surveillance AreasOf the National surveillance Plan(Ministery Agriculture and Food)

MCDMulticriteria

Decision:

Logistic regression model

USEFULINFORMATION ����IMPROVE

SURVEILLANCE PLANS

HighHigh

LowLow

RiskRisk valuesvalues ((OctoberOctober))

ProvincesProvinces

EuropeEurope

Risk of ocurrence of Avian Influenza in wildbirds

Spatial analysis to EVALUATE currentstrategy in health surveillance in Europe.

Co-kriging

Probability of ocurrence of Avian Influenza

Test pointsAvian Influenza cases

+ co-variableWetlands (>20.000 Waterbirds)

+ co-variantePoultry density

• Geostatistical analysis:Co-kriging

Co-kriging

Probability of ocurrence of Avian Influenza

• Geostatistical analysis:Co-kriging

Co-kriging

Probability of ocurrence of Avian Influenza

NLNL

DEDE

USEFULINFORMATION ����EVALUATE

SURVEILLANCESTRATEGIES

• Geostatistical analysis:Co-kriging

SPSP

Sampling> Risk Avian Influenza

Sampling< Risk Avian Influenza

• Grubb’s test, P<0.01

• Spearman’s coefficient

$

$

Veterinary Authorities and

Organisations

Identify HOT SPOT of RISK� Adequate control mesures

Help to take decisions for� TARGET SURVEILLANCE (According to EC

recommendations)

Spatial Analysis is an essential tool for Animal Health

CONCLUSIONS

Reduce health costs and improve efficiency

of veterinary intervention

Increase INFORMATION about dynamic of diseases � improve

PREVENTION & CONTROL PLANS� Prevent or reduce consequences

EVALUATE control and prevention strategies

Laguna de Pitillas (Navarra) http://www.navarra.es/home_es/Actualidad/Informes

Financial support: CC08-020, FAU2008-00001-C02-01