The US hasn't seen a human bird flu case in 3 months. Experts are wondering why - Medical Xpress

The US hasn't seen a human bird flu case in 3 months. Experts are wondering why  Medical XpressBird flu in humans hasn't officially been seen in U.S. in 3 months: "We just don't know why"  CBS NewsThe worst of avian flu outbreak may be over in California, health officials say  San Francisco ChronicleThe US hasn’t seen a human bird flu case in 3 months. Experts are wondering why  Colorado Hometown WeeklyThe US hasn't seen a human bird flu case in thre