1 / 21

Sentinel Bird Surveillance for West Nile virus

Sentinel Bird Surveillance for West Nile virus. Nicholas Komar, Sc.D. CDC-Arbovirus Diseases Branch Fort Collins, CO. West Nile Virus Transmission Cycle. Mosquito vector. Incidental infections. WNV. WNV. Incidental infections. Bird reservoir hosts. WNV Surveillance Modalities.

RexAlvis
Download Presentation

Sentinel Bird Surveillance for West Nile virus

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Sentinel Bird Surveillance for West Nile virus Nicholas Komar, Sc.D. CDC-Arbovirus Diseases Branch Fort Collins, CO

  2. West Nile Virus Transmission Cycle Mosquito vector Incidental infections WNV WNV Incidental infections Bird reservoir hosts

  3. WNV Surveillance Modalities • Dead birds (especially crows) • Mosquitoes • Live wild bird sentinels • Live captive sentinels (e.g. chickens) • Veterinary surveillance • Human surveillance

  4. The success of sentinel bird surveillance depends solely on the effort expended by surveillance workers.

  5. WNV Surveillance Totals, 2000Reported to CDC thru 1/25/01 * Confirmed & Probable cases; ** includes 7 from NYC

  6. WNV seroprevalence, cumulative % Pos for Neut Ab Species NE Queens ’99 S.I.’00 Chicken 63 6 Pigeon 27 54 Mallard 6 8 House sparrow 60 9 Cardinal -- 69 Catbird -- 33 Dog 11 -- Horse 6 -- Human 2.6 0.5

  7. Can Chickens be used as Sentinels? • Highly susceptible (for development of antibodies) • Resistant to mortality • Non-infectious to eachother • Non-infectious to handlers • Non-infectious to mosquitoes

  8. Pathogenicity of WNV in Chickens USDA-APHIS-NVSL: Senne, Pederson, Hutto, Taylor, Schmitt, Panigrahy Avian Dis 44:642-649, 2000

  9. Mean Days Mean PeakSpecies n Infectious* Viremia ** ci***Blue jay 2 4 12.3 2.4Common grackle 6 3 9.4 1.0House sparrow 6 3 8.9 0.9House finch 2 6 8.8 0.8American robin 2 3 8.5 0.6Red-wing. blackbird 3 3 8.1 0.5Mallard 2 3 6.7 0.3European starling 6 2 6.0 0.1Canada goose 3 0 4.7 0American coot 1 0 4.6 0Rock dove 6 0 4.3 0Chicken 16 0 3.2 0Ring-neck Pheasant 3 0 2.7 0 * Infectious viremia = log 5 or greater per ml serum; ** log pfu/ml serum *** ci = susceptibility * mean infectiousness * days infectious Do chickens develop WN viremia?

  10. Features of a Sentinel Chicken Program • Chicken flocks established at known transmission foci • Birds are bled periodically • Serum samples sent immediately for testing • HI or M-ELISA test used for screen • N test for confirmation (3 days) • Positives replaced for accurate monitoring

  11. New York City’s Sentinel Chicken Program • Details provided by Dr. Bryan Cherry • 13 coops (7 birds each) at live poultry markets in 4 boroughs, plus one flock of 15 in Staten Island • 7 of 106 seroconverted (tested at Cornell) • One dead chicken tested WNV+ by NYSDOH

  12. New York State’s Sentinel Chicken Program • Details from Dr. Millie Eidson, Dr. Greg Ebel • Flocks placed in 4 counties: Suffolk (103 birds), Rockland (24), Westchester (70), Onondaga (47) • Sera screened by G-ELISA, confirmed by PRNT • 1 of 244 seroconverted 4 Aug in Westchester

  13. New Jersey’s Sentinel Chicken Program • Details provided by Cheryl Farello, Dr. Bob Eisner • All 21 counties maintained 1-2 flocks of 3 birds each (more flocks in Ocean, Monmouth) • 4 of 102 seroconverted • Sera screened by HI, confirmed by PRNT at USDA-APHIS-VS-NVSL • Dates of seroconversions are 27-29 Sep from Sussex, Middlesex, Morris, Essex counties

  14. Features of a Sentinel Wild Bird Program • Sampling sites established at known transmission foci • Wild birds are captured periodically and banded • Serum samples sent immediately for testing. Virus isolation may be attempted. • HI, ELISA or PRNT used for screen • PRNT for confirmation (3 days) • Hatch-year birds most useful, or recaptured adults, of targeted species

  15. Summary of Wild Bird Surveillance, NYC Species n No. POS % House Sparrow 440 3 0.7% Other 150 1 0.7% Line list:Jul 21 House Sparrow Queens-Floral ParkAug 2 Mockingbird Brooklyn-Sunset ParkAug 9 House Sparrow Bronx-Orchard BeachAug 21House Sparrow Queens-Forest Park

  16. First WNV Surveillance Events, 2000 Sentinel wild bird, Suffolk Horse, Richmond Sentinel Chicken, Westchester Oc. japonicus, Westchester; Cx. pipiens, Richmond Viral activity (inferred) Human, Richmond Crow, Suffolk Crow, Richmond Mar Jun Jul Aug Apr Sep Oct

  17. Time’s Up!

  18. Does a dead bird represent local WNV transmission?

  19. Culex sp. WN virus infectionsJuly 15-24, 2000 * Minimum Infection Ratio = # infected/1000 tested

  20. House Sparrow SeropositivesJuly 15-24, 2000

More Related