Focal amplification and suppression of West Nile virus transmission associated with communal bird roosts in northern Colorado

Details

• Alternative Title:
  J Vector Ecol
• Personal Author:
  Komar, Nicholas ; Panella, Nicholas A. ; Burkhalter, Kristen L.
• Description:
  To explain the patchy distribution of West Nile virus (WNV), we propose that avian immunity encountered by Culex vectors regulates WNV transmission, particularly at communal bird roosts. To test this hypothesis, we selected two test sites with communally roosting American robins (Turdus migratorius) and two control sites that lacked communal roosts. The density of vector-vertebrate contacts, represented by engorged Culex pipiens, was 23-fold greater at test sites compared to control sites, and the density of blood-engorged Cx. pipiens measured in resting mosquito traps correlated positively with the presence of robins and negatively with the presence of other birds, confirming an attraction to robins for blood feeding. WNV transmission was alternately up-regulated (amplification) and down-regulated (suppression) at both test sites. At one test site, infection in resting Cx. pipiens surged from zero to 37.2 per thousand within four weeks, and robin immunity rose from 8.4% to 64% before reducing to 33%. At this site, ten potentially infectious contacts between vector and vertebrates (including nine robins and a mourning dove [Zenaida macroura]) were documented. Infectious vector-vertebrate contacts were absent from control sites. The use of infectious vector-vertebrate contacts, rather than infected mosquitoes, to evaluate a transmission focus is novel.
• Subjects:
  Animals Bird Diseases Columbidae Culex Female Host-Pathogen Interactions Mosquito Vectors Songbirds West Nile Fever West Nile Virus
• Keywords:
  Arbovirus Bird Communal Bird Roost Ecology Mosquito Transmission Vector
• Source:
  J Vector Ecol. 43(2):220-234
• Pubmed ID:
  30408295
• Pubmed Central ID:
  PMC7083205
• Document Type:
  Journal Article
• Funding:
  CC999999/ImCDC/Intramural CDC HHSUnited States/
• Place as Subject:
  Colorado
• Volume:
  43
• Issue:
  2
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha256:e114904fa87166268de7dd5c4ac5813003b5edb6ce2258f0e1152e95d46b357b
• Download URL:
  https://stacks.cdc.gov/view/cdc/86024/cdc_86024_DS1.pdf
• File Type:
  [PDF - 664.45 KB ]