Avian host community structure and prevalence of West Nile virus in Chicago, Illinois.
Vertebrate host diversity has been postulated to mediate prevalence of zoonotic, vector-borne diseases, such that as diversity increases, transmission dampens. This "dilution effect" is thought to be caused by distribution of infective bites to incompetent reservoir hosts. We quantified avian species richness, avian seroprevalence for antibodies to West Nile virus (WNV), and infection of WNV in Culex mosquitoes, in the Chicago metropolitan area, Illinois, USA, a region of historically high WNV activity. Results indicated high overall avian seroprevalence and variation in seroprevalence across host species; however, there was no negative correlation between avian richness and Culex infection rate or between richness and infection status in individual birds. Bird species with high seroprevalence, especially northern cardinals and mourning doves, may be important sentinels for WNV in Chicago, since they were common and widespread among all study sites. Overall, our results suggest no net effect of increasing species richness to West Nile virus transmission in Chicago. Other intrinsic and extrinsic factors, such as variation in mosquito host preference, reservoir host competence, temperature, and precipitation, may be more important than host diversity for driving interannual variation in WNV transmission. These results from a fine-scale study call into question the generality of a dilution effect for WNV at coarser spatial scales.
Loss
Scott R
SR
Department of Natural Resources and Environmental Sciences, University of Illinois, Shelford Vivarium, 606 E. Healey St., Champaign, IL 61820, USA. lossx004@umn.edu
Hamer
Gabriel L
GL
Walker
Edward D
ED
Ruiz
Marilyn O
MO
Goldberg
Tony L
TL
Kitron
Uriel D
UD
Brawn
Jeffrey D
JD
D000818:Animals; D001483:Base Sequence; D001717:Birds / Q000145:classification / Q000821:virology*; D002641:Chicago; D003465:Culex / Q000821:virology; D017931:DNA Primers; D004197:Disease Reservoirs; D007303:Insect Vectors; D016036:Seroepidemiologic Studies; D013045:Species Specificity; D014902:West Nile virus / Q000302:isolation & purification*
D017931:DNA Primers