Avian Influenza
The infection: Avian influenza, caused by strains of influenza A viruses native to birds.
Its threat potential: Highly pathogenic avian flu strains can be incredibly transmissible and fast-killing among wild and domestic birds. Since last October, an epidemic caused by an avian H5N1 strain has spread across the globe, leading to the deaths of millions of birds. Bird-to-human transmission of these germs is uncommon, usually requiring close, prolonged contact, and it’s even rarer that someone will then spread the infection to others. But over time, the worry is that one of these strains will pick up the right set of mutations that allow it to be just as contagious and fatal in humans as it can in birds, setting the stage for a horrific pandemic.
Symptoms and treatment: Humans usually don’t get sick from avian influenza viruses, but symptoms can resemble the typical respiratory infection. Some past outbreaks in humans have been especially deadly, however, killing close to half of those infected.
