A New Pandemic Threat On the Horizon: H7N9, by TXnurse
Influenza A viruses originate from various avian species, and almost exclusively begin in China. Influenza A viruses have always infected many different species of birds. Often initially seen in one species, they frequently cross over and cause illness in another species, this is called mixing, mutation or antigenic drift. This is how new subtypes of viruses are created. Eventually these viruses progress until they mutate enough to become infective to mammalian hosts (us). These viruses can be highly infective, easily transmissible and very lethal in humans. Most of us have probably heard of the H1N1 virus that took a substantial …