Early-Season Avian Deaths from West Nile Virus as Warnings of Human Infection
Figure 1. Counties reporting avian deaths and human illness caused by West Nile virus (WNV), January 1–December 31, 2001. Counties reporting human illness are outlined in red. The color within the county indicates the date when the first avian death from WNV was reported in that county. Counties that report dead birds early in the year are more likely to report subsequent disease cases in humans.