Bird flu is increasingly sparking concern across the country and in Illinois, following news this week of the first human death from the virus in the U.S., and of birds found throughout Illinois with suspected cases of the illness. Doctors, however, say there’s no need to panic at this point — though they’re watching the virus’s progression closely. The Tribune spoke with local experts to find out what Illinois residents should know about bird flu right now. What is the bird flu? The bird flu is a disease caused by avian influenza A viruses that mostly spreads between birds.