Interesting new development--a 4-year old, symptom-less carrier has been found in Beijing.

The boy's neighbor bought chicken from the parents of the 7-year old girl, who is Beijing's first confirmed H7N9 case. The parents of the girl sell live chickens. Since the boy did not have direct contact with the chicken sellers or any chicken sold by the chicken sellers, it seems likely that he was infected through another person.

That could be good news, if it turns out that far more people than we currently know have actually gotten H7N9 and not even noticed it. Then it wouldn't be so lethal. In other words, it could mean H7N9 is far milder than initially thought.

Or, it could be bad news, if the virus is actually highly lethal and a small percentage of carriers allow the disease to spread undetected and unknowingly far and wide, person-to-person. The virus also doesn't seem to sicken birds much, if at all, which makes monitoring its spread in the bird population much more difficult.

Up to 63 cases now, last that I've read. That already exceeds the number of H5N1 cases ever seen in China over the course of a decade.