Parmley Avian Influenza May2006 000

Avian Influenza:The 2005 Canadian wild bird survey: 

Avian Influenza: The 2005 Canadian wild bird survey ADED May 16, 2006

Background: 

Background Planning – initiated December 2005 Federal and provincial agencies: Wildlife Agriculture Public Health

Goals: 

Goals To inventory influenza A viruses that occur in Canadian wild birds To characterize influenza A viruses isolated from Canadian wild birds To survey Canadian wild bird populations for the presence of particular influenza A viruses To establish an archive of influenza A virus strains To build and maintain integrated, multi-agency field, laboratory, regulatory and communications capacity

Objectives: 

Objectives To sample 6 populations of wild ducks in Canada in the summer and fall of 2005 To characterize all influenza A viruses detected in these samples

Material and Methods: 

Material and Methods Collection of samples Screening by PCR Further characterization

Collection of samples: 

Collection of samples Lead agency: Canadian Wildlife Service (Environment Canada) Also Ducks Unlimited (BC) and Ontario Ministry of Natural Resources (ON) Piggy backed onto other existing projects Bird banding Cloacal swabs

Sample size and more…: 

Sample size and more… 800 birds to be sampled from each region 500 mallards 300 other species Live, healthy young ducks Focus on detecting viruses not estimating prevalence

Sampling locations: 

Sampling locations 6 regions selected: BC Alberta Manitoba Ontario Quebec Atlantic Canada Multiple sites within each region total of 56 sites

Primary labs : 

Primary labs All cloacal swabs collected were submitted to a local diagnostic lab: Animal Health Centre - BC Ministry of Agriculture (Abbotsford, BC) Alberta Agriculture’s Veterinary Diagnostic Laboratory (Edmonton, AB) Manitoba’s Veterinary Services Branch – Ministry of Agriculture, Food and Rural Initiatives (Winnipeg, MB) Animal Health Laboratory – University of Guelph (Guelph, ON) Quebec’s INSA – Reseau des laboratories – Ministere de l’agriculture, des pecheries et de l’alimentation (Montreal, QU) Atlantic Veterinary College – University of Prince Edward Island (Charlottetown, PE)

Primary lab responsibilities: 

Primary lab responsibilities Run matrix PCR on all cloacal swabs to screen each sample for influenza A viruses Is the virus present? Run H5 and H7 PCR on all samples that tested positive by matrix PCR Are H5 or H7 virus subtypes present? Isolate viruses from samples that tested positive by matrix PCR What virus subtypes are present in healthy ducks?

Secondary labs and their responsibilities: 

Secondary labs and their responsibilities National Centre for Foreign Animal Disease (NCFAD-CFIA) in Winnipeg. H and N typing Genetic analyses National Microbiology Lab (NML-PHAC) in Winnipeg Genetic analyses National archive of viruses What virus subtypes are present in healthy ducks?

Results to date: 

Results to date Sampling completed as of December 2005 4405 cloacal swabs collected PCR testing (matrix and H5/H7) complete Descriptive results high-lighted here Virus isolation and further characterization is ongoing

PCR Results: 

PCR Results All H5 Strains were low pathogenic and all were North American Strains

Proportion (number) of samples from each sample region : 

Proportion (number) of samples from each sample region

Proportion (number) of the total matrix PCR positive results by region : 

Proportion (number) of the total matrix PCR positive results by region 22% (353) 5% (77) 6% (94) 24% (382) 20% (318) 1% (8) 22% (340)

Proportion (number) of the total H5 PCR positive results by region: 

Proportion (number) of the total H5 PCR positive results by region 3% (6) 13% (28) 77% (161) 4% (9) 2% (4)

Sample collection dates: 

Sample collection dates 83% of all samples were collected in August

PCR results by month: 

PCR results by month

Sample collection: weekly variation: 

Sample collection: weekly variation

Proportion positive by week: 

Proportion positive by week H5 PCR Matrix PCR

Species summary stats: 

Species summary stats 61% of samples from mallards (range from 12% in Newfoundland to 81% in BC) Mallards more likely to test positive by matrix PCR than other species of ducks combined (p<0.001) 44% (1148/2600) of mallards tested positive and 25% (424/1668) of other ducks tested positive 14 other species of ducks had at least 1 specimen test positive by matrix PCR

Age: 

Age 80% of birds sampled were hatched in 2005 41% of juvenile birds tested positive on matrix PCR compared with 23% of birds from other hatch years (p<0.0001)

Sex: 

Sex 55% of samples collected from males and 44% from female 39% male birds tested positive for matrix PCR compared with 35% of females (p<0.05).

Slide28: 

2005 Survey Collaborators Sample Collection: A. Breault P. Pryor D. Caswell N. North C. Davies J. Rodrigue K. McAloney J. Turner H. Whitney C. Francis L. Howes Virology: J. Pasick T. Booth J. Robinson R. King G. Nayar D. Ojkic M. Fortin S. Elahi F. Kibenge Data Management: R. Templeman K. Brown A. Templeman J. Brown Program Management: P. Zimmer J. Parmley P. Sockett P-Y. Daoust S. Lair I. Barker T. Bollinger R. Lewis S. Renwick P. Buck M. Swendrowski And ALL their many co-workers

Discussion Points: 

Discussion Points High proportion of test positive birds: Results here are based on initial PCR screening Most other studies report findings based on viral isolates 26 years of data from Alberta revealed an average of 22% positive: range <5 to >40% (Krauss et al 2004)

Discussion Points: 

Discussion Points Variation by region: Matrix: why low virus recovery from prairie samples? In Alberta most samples collected in August (82%), from mallards (49%) and from juveniles (80%) In Manitoba most samples were collected in August (99%), from mallards (62%) and from juveniles (58%) Cyclical temporal patterns identified from data collected over 26 years from Alberta

Discussion Points: 

Discussion Points Variation by region: b. H5: why high virus recovery from BC samples? Samples all from one geographic area (2 lakes near to each other) H5 not a commonly isolated virus from wild birds (H3, H4, H6 most commonly detected) H5 only accounted for 0.2% of isolated viruses (Krauss et all 2004) Plan to sample the same area again in 2006 but will also sample additional birds from other sites

Discussion Points: 

Discussion Points Proportion of test positive through the season Unexpected and variable weekly trends Small sample size in all months except August Others have shown that virus recovery declines through the season This has been attributed to increasing herd immunity as the season progresses (Stallknect et al 1988)

Discussion Points: 

Discussion Points More mallards tested positive than other species but not in all regions No difference in Ontario: high proportion of wood ducks in the sample and 68% of these tested positive No difference in Newfoundland but small sample size and few mallards Manitoba?? Diving versus dabbling ducks