Volume 11, Number 3—March 2005
Research
West Nile Virus Risk Assessment and the Bridge Vector Paradigm
A. Marm Kilpatrick*
, Laura D. Kramer†, Scott R. Campbell‡, E. Oscar Alleyne§, Andrew P. Dobson¶, and Peter Daszak*
, Laura D. Kramer†, Scott R. Campbell‡, E. Oscar Alleyne§, Andrew P. Dobson¶, and Peter Daszak*Table
Risk of mosquito species transmitting West Nile virus (WNV) to humans
| Species | Relative abundance | WNV MIR* | Vector competence† (reference) | Fraction mammal‡ | Risk | % Risk |
|---|---|---|---|---|---|---|
| Aedes vexans | 20.7 | 0.05 | 0.17 (16) | 0.86 (126) | 0.14 | 4.5 |
| Coquillettidia perturbans | 11.3 | 0.01 | 0.11 (17) | 0.83 (191) | 0.01 | 0.5 |
| Culex pipiens + Cx. restuans | 37.2 | 0.95 | 0.38 (16–18) | 0.19 (373) | 2.52 | 80.2 |
| Cx. salinarius | 0.6 | 0.85 | 0.36 (17) | 0.67 (91) | 0.12 | 3.9 |
| Culiseta melanura | 5.2 | 0.17 | 0.28 (19)§ | 0.11 (141) | 0.03 | 0.8 |
| Ochlerotatus canadensis | 14.9 | 0.00 | 0.55 (16,18)¶ | 1.00 (107) | 0.00 | 0.0 |
| Oc. japonicus | 0.5 | 0.33 | 0.93 (16) | 0.95 (57) | 0.16 | 5.0 |
| Oc. sollicitans | 2.0 | 0.07 | 0.16 (16) | 1.00 (28) | 0.02 | 0.7 |
| Oc. trivittatus | 7.6 | 0.05 | 0.55 (16,18)¶ | 0.64 (115) | 0.14 | 4.4 |
*MIR, minimum infection rate.
†The fraction of WNV-infected mosquitoes that will transmit virus in a subsequent bite.
‡Number of mosquito blood meals identified in parentheses (9,10, Kramer et al., unpub. data).
§Vector competence value taken from study on Cs. inornata. Risk increases to 0.09 and 3.0%, assuming a maximum vector competence of 1.0.
¶Genus average used. Risk with a vector competence of 1.0 would be 0 and 0% for Oc. canadensis and 0.25 and 8.0% for Oc. trivittatus.
