pandemic

The US has recorded its first death due to avian influenza. The man had been infected by a H5N1 variant with a genetic mutation, helping it target upper respiratory tract receptors – one also seen in the Canadian teen who fell critically ill last year.

Scientists are again on high alert, as whole genome sequencing of the H5N1 virus has revealed that it is capable of multidirectional infections across species. While human risk is low, it's a step forward for the pathogen in this biological arm's race.