These county and county equivalent data show the results of tests on blood samples from sentinel chickens, provided by local health officials. Sentinel chickens are birds placed in cages that are exposed to mosquitoes in the area. Chickens that are bitten by infected mosquitoes develop antibodies, but are not otherwise affected by the virus. Note that the map includes all areas of positive (confirmed or probable) WNV results, but not necessarily all areas with submitted samples or no reports.
| Cumulative Report Maps for the year 2002, California | |||
|---|---|---|---|
| Cumulative Human | Cumulative Veterinary | Cumulative Mosquito | Cumulative Bird |
California Department of Health