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Ferrets react to flu much like humans do. Photo: Flickr user dmcneil

The secret to airborne bird flu is out. Dutch researchers published a controversial paper yesterday that detailed how they caused a deadly strain of H5N1 bird flu to transform from a disease transmittable only through contact to one that could be transmitted through the air.

The team used ferrets as test subjects, since they respond to flu much as humans do. The technique for infecting them is surprising simple: basically, the scientists did everything to the ferrets health experts tell people not to do during flu season. At Popular Science, Rebecca Boyle describes the procedure:

They [mutated the virus] by exposing two ferrets to two different flu variants, and swabbed their noses and throats every day for four days. The animals were euthanized on the fourth day, and their infected nasal tissue was used to expose another ferret. This process repeated six times, and then the researchers also induced the ferrets to sneeze. They collected the sneezes in a petri dish and then exposed additional ferrets to it.

As the disease mutated, it lost strength, so ferrets exposed to their compatriot’s sneezes were able to fight it off. But, as the New York Times reports, “it did kill when high doses were squirted into the animals’ nostrils.”

New flu season tip? Don’t let anyone squirt flu directly into your nose.

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