AI Surveillance – Murdoch University_SFenwick

8/3/2019 AI Surveillance Murdoch University_SFenwick

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AI Surveillance MurdochUniversity projectsREVASIA meeting, Phnom

Penh, 17th June 2009

Professor Stan FenwickVeterinary Public Health


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Current and completed AI projects atMurdoch University

Epidemiology of HPAI in Bali, Indonesia

Surveillance for HPAI in wild birds in Thailand

Movement of birds through live bird markets in Bali and

Lombok and their role in the epidemiology of avian influenza Development of a risk based surveillance system todemonstrate freedom from Highly Pathogenic Avian Influenza(HPAI) in Timor Leste

Development of a marker vaccine for AI surveillance

Development of a DNA vaccine for AI in chickens

Epidemiology of HPAI and vaccination efficacy in Vietnam


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Epidemiology of AI in Bali, Indonesia


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Epidemiology of AI in Bali, Indonesia(Tze Hoong Chua PhD)

1. Laboratory evaluation of five influenza antigendetection tests to estimate their diagnosticsensitivity

2. H5N1 infection in healthy village poultry in Bali3. Risks for spread of viruses from live poultry

markets in Bali

4. Phylogenetic relationship of H5N1 virusescirculating in the village study sites


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1. Overall sensitivities of rapid antigen testsranged from 36.3% to 51.4%. Could be usedfor rapid and preliminary flock investigationsof H5N1 outbreaks in sick and dead birds butshould not be used for surveillance testing ofclinically healthy birds

2. Surveillance recovered H5N1 HPAI virus at a

low isolation rate (0.09% in chickens and0.13% in ducks) in apparently healthy villagepoultry.


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Surveillance activities in

villages in Bali


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3. Isolates from the surveillance of apparently healthybirds shared close phylogenetic relationship withpoultry viruses from outbreak cases (under subclade

2.1) and also contained the characteristic HPAImolecular pathotypes.

4. A case-control study of village household flocks wasperformed which identified risk factors that couldinfluence the occurrence of H5N1 HPAI. Sale ofpoultry to collectors remained significantly associatedwith highly pathogenic poultry diseases (p0.1)


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Surveillance for HPAI in wild birds inThailand

(Jarunee Siengsenan PhD)

1. Existing data analysis from Thai Govt. surveillance

2.2. Serology and virology surveillance program for HPAISerology and virology surveillance program for HPAI

H5N1 in wild birdsH5N1 in wild birds3.3. Molecular epidemiology of virus isolatesMolecular epidemiology of virus isolates

4. Observational study of poultry/wild bird interactionson selected farms

5. Quantitative risk assessment


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Study area selection based on district whereinfections were identified in open billed storks

Banglane District,Nakornpratom province

Klongnokkratong

subdistrict

Bangpasri

subdistrictBanglane

subdistrict

Bangsripa

subdistrict


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Rice paddy fields

Villages and farms


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Field sample collection Targeting multiple

species/multiple trappingtechniques workingwith Dept of Wildlife

Samples including throatswabs, cloacal swabs, andserum


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Laboratory tests Viral isolation: MDCK cell culture

Haemagglutination test (HA) RT PCR: specific primers to H5, N1, and M genes

Neutralization Test (NT)

Gene sequencing

Molecular analysis Sequence results were compared with other Thai

sequences submitted to Genbank to generatephylogenetic trees. Softwares including BioEdit,

Mega, and ExPasy were used to create trees.


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Total 421 healthy wild birds sampled(44 species)No concurrent poultry outbreaks Sero-prevalence in wild birds was 2.1% (8 out of 385 samples)

Species tested positive by NT: Rock Pigeon (Columba livia)

Asian Pied Starling (Gracupica contra) Spotted Dove (Streptopelia chinensis) Oriental Magpie Robin (Copsychus saularis) Blue-tailed bee-eater (Merops philippinus) Myna (Acridotheres spp.) Pond heron (Ardeola spp.)

Species highlighted in red are common resident birds whichhave close contact with poultry on farms or in paddy fields


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Virus prevalence was 0.5% (2 out of 421samples). Positive samples were from oneAsian Pied Starling (Gracupica contra) and oneWhite Vented Myna (Acidotheres grandis) both common resident species on farms

White vented myna

Asian pied starling


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Both viral samples clustered with other samples isolatedin Thailand between 2004 and 2006

Clinically healthy resident wild bird species showedevidence of previous or current H5N1 infection with

H5N1 viruses albeit at low prevalence. This data does not elucidate the direction ofmovement or source of virus transmission to the wild

birds (domestic poultry to resident wild birds or viceversa; origin from migratory birds, domestic poultry orindirectly via human movements)


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Movement of birds through live bird marketsin Bali and Lombok and the role of markets

in the epidemiology of AI

(Johanna Johnson PhD)

1. Cross-sectional studies to determine trends inquantity, sources, destinations and management

of chickens and ducks at selected markets in Baliand Lombok

2. Detection of HPAI H5N1 virus in selected markets

in Bali and Lombok3. Qualitative assessment of risk associated withchicken and duck movements

4. Social network analysis of market movements


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Questionnaires for Collectors, Vendors andCustomers developed and applied at selected markets

in Bali and Lombok


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Cross-sectional studies of live birdmarkets in Bali and Lombok

1. Live birds in the supply chain come from varioussources in the island such as villages, and sub-district

traditional markets

2. Birds from backyard farmers are collected by villagelevel collectors then brought to sub-district anddistrict level live bird markets. From these markets the

birds are purchased by customers for differentpurposes such as consumption (households, andrestaurants), offerings in ceremonies and religiousfestivals, and for replacement stock for farmers


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Cross-sectional studies of live birdmarkets in Bali and Lombok

3. This study found that the numbers of birds at markets tends toincrease during certain times and months of the year such asGalungan and Kuningan in Bali, and Fasting and Hari Raya

months in Lombok .4. Vendors, Collectors, and Customers all want and tend to buy

healthy birds

5. Transportation and management of birds involve poorbiosecurity practices. Collectors and vendors do not separatebirds according to bird species and sources. Birds are mixed incages during transportation and at markets. Birds are also

moved from one market to another with mobile vendors andcollectors


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? HPAI infection in ducklingat a poultry market andclose contact with child


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Development of a risk based surveillancesystem to demonstrate freedom from HPAIin Timor Leste

(Acacio Amaral PhD)

1. To demonstrate the absence of Highlypathogenic Avian Influenza (HPAI) inTimor Leste.2. To define the potential pathways for theintroduction of AI into East Timor andcarry out a qualitative and quantitativeanalysis of the risks .


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Development of a risk based surveillancesystem to demonstrate freedom from HPAIin Timor Leste

1. Planned, targeted surveillance strategies forvirus detection2. Development of questionnaires for farmers,livestock officers, quarantine and other relatedstakeholders3. Identification of possible risk pathways forHPAI introduction from infected countriesinto the country


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Development of a risk based surveillancesystem to demonstrate freedom from HPAI

in Timor Leste

4. Identification of risk factors for diseasetransmission to domestic poultry from wildbirds5. Collection of samples from targeted highrisk areas at the border of Timor Leste andIndonesia


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Development of a marker vaccine forAI surveillance(Trevor Ellis, Cassie James, Stan Fenwick, DIVA Solutions)

1. Tetanus toxoid (TT) evaluated as an exogenous marker forpoultry vaccination2. No evidence of natural antibodies to TT in poultry3. ELISA developed to detect Ab in chickens, competitive

ELISA for detection in ducks4. Long-lasting Ab response post TT vaccination in chickens

and ducks

5. No interference with immunity when TT and AI vaccinesgiven together, evaluated via challenge trial with H5N16. Trial batch of TT/H5N2 vaccine formulated by Intervet and

tested in a field trial in Hong Kong, detection of TT Ab

allowed rapid detection of vaccinated birds


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Benefits of an AI marker vaccine

1. TT is a highly suitable marker for AI vaccination in poultryallowing simple and effective monitoring of AI vaccinationstatus via cheap, rapid ELISA testing

2. TT is a good candidate as it is cost-effective, easy tomanufacture, and is a commercially available vaccine forfood animals and humans

3. The versatility and robustness of the exogenous TT marker

means that it can be formulated with any vaccine type(inactivated, reverse genetics) or with any poultry vaccine(AI, ND)


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Benefits of an AI marker vaccine

4. TT strategy can improve control of poultry movementsfrom farms to markets based on serological evidence ofsuccessful vaccination using approved vaccines as birds wouldneed to show positive antibody responses to the TT marker

with concordant HA antibody levels that were adequate forprotection

5. Other benefits include evaluation of vaccinationmethodology and efficacy, evidence of vaccination coverage- market and slaughterhouse surveillance


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Epidemiology of HPAI and vaccinationcoverage in Vietnam(Stephanie Desvaux PhD)

1. To estimate vaccination effectiveness (qualitativeand quantitative evaluation) within chicken andduck farms in a selected area of northern Vietnam

2. To study the serological response profile ofvaccinated birds and the duration of immunityunder field conditions

3. To estimate the backyard poultry populationdynamics and vaccination coverage in selectedhouseholds in the study area


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Documents

AI Surveillance – Murdoch University_SFenwick