, Volume 158, Issue 4, pp 699–708 | Cite as

Ecological correlates of risk and incidence of West Nile virus in the United States

  • Brian F. AllanEmail author
  • R. Brian Langerhans
  • Wade A. Ryberg
  • William J. Landesman
  • Nicholas W. Griffin
  • Rachael S. Katz
  • Brad J. Oberle
  • Michele R. Schutzenhofer
  • Kristina N. Smyth
  • Annabelle de St. Maurice
  • Larry Clark
  • Kevin R. Crooks
  • Daniel E. Hernandez
  • Robert G. McLean
  • Richard S. Ostfeld
  • Jonathan M. Chase
Community Ecology - Original Paper


West Nile virus, which was recently introduced to North America, is a mosquito-borne pathogen that infects a wide range of vertebrate hosts, including humans. Several species of birds appear to be the primary reservoir hosts, whereas other bird species, as well as other vertebrate species, can be infected but are less competent reservoirs. One hypothesis regarding the transmission dynamics of West Nile virus suggests that high bird diversity reduces West Nile virus transmission because mosquito blood-meals are distributed across a wide range of bird species, many of which have low reservoir competence. One mechanism by which this hypothesis can operate is that high-diversity bird communities might have lower community-competence, defined as the sum of the product of each species’ abundance and its reservoir competence index value. Additional hypotheses posit that West Nile virus transmission will be reduced when either: (1) abundance of mosquito vectors is low; or (2) human population density is low. We assessed these hypotheses at two spatial scales: a regional scale near Saint Louis, MO, and a national scale (continental USA). We found that prevalence of West Nile virus infection in mosquito vectors and in humans increased with decreasing bird diversity and with increasing reservoir competence of the bird community. Our results suggest that conservation of avian diversity might help ameliorate the current West Nile virus epidemic in the USA


Dilution effect Disease ecology Emerging infectious diseases Ecosystem service 



We thank D. Allan, L. Blaustein, J. Bradford, S. Crawford, C. Frazier, P. Green, F. Keesing, T. Knight, B. McCauley, P. Morin, C. Osenberg, K. Schmidt, J. Scott, G. Storch, D. Tulloch, K. Yates, the Chase lab group, the Rutgers Center for Remote Sensing & Spatial Analysis laboratory and two anonymous reviewers for discussions, comments, and logistical support. The cooperation of numerous private land owners and public land managers made this project feasible, as did logistical support from Washington University and the Tyson Research Center. Financial support was provided by Washington University (to J.M.C.), and the Webster Groves Nature Study Society and Saint Louis Audubon Society (to B.F.A.). The authors declare that the studies described herein comply with the laws of the USA.


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Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Brian F. Allan
    • 1
    Email author
  • R. Brian Langerhans
    • 2
  • Wade A. Ryberg
    • 1
  • William J. Landesman
    • 3
  • Nicholas W. Griffin
    • 1
  • Rachael S. Katz
    • 4
  • Brad J. Oberle
    • 1
  • Michele R. Schutzenhofer
    • 5
  • Kristina N. Smyth
    • 6
  • Annabelle de St. Maurice
    • 7
  • Larry Clark
    • 8
  • Kevin R. Crooks
    • 9
  • Daniel E. Hernandez
    • 10
  • Robert G. McLean
    • 8
  • Richard S. Ostfeld
    • 11
  • Jonathan M. Chase
    • 1
  1. 1.Department of BiologyWashington UniversitySaint LouisUSA
  2. 2.Museum of Comparative Zoology, Department of Organismic and Evolutionary BiologyHarvard UniversityCambridgeUSA
  3. 3.Department of Ecology, Evolution and Natural ResourcesRutgers UniversityNew BrunswickUSA
  4. 4.Department of EntomologyNorth Carolina State UniversityRaleighUSA
  5. 5.Division of Science and MathematicsMcKendree UniversityLebanonUSA
  6. 6.Department of BiologySaint Louis UniversitySaint LouisUSA
  7. 7.University of Rochester School of Medicine and DentistryRochesterUSA
  8. 8.United States Department of AgricultureNational Wildlife Research CenterFort CollinsUSA
  9. 9.Department of Fishery and Wildlife BiologyColorado State UniversityFort CollinsUSA
  10. 10.Division of Natural Sciences and MathematicsThe Richard Stockton College of New JerseyPomonaUSA
  11. 11.Cary Institute of Ecosystem StudiesMillbrookUSA

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