H5N1 Bird Flu updates

This a good new/bad news situation. The good news—excellent, actually—is that the Missouri case that might have been human-to-human transmission very probably was not. For one, the health care contacts were not infected with H5N1, and for another, the household contact was very likely infected at exactly the same time as the index patient and therefore exposed to the original source of the infection rather than catching it from—or giving it to—the index patient.

The bad news, well, it could be worse (though my guess it that now it probably will be at some point, just not today). Yesterday the National Institute of Allergy and Infectious Disease (NIAID) broke the news that virus isolated from people infected by bovine strains of bird flu can be transmitted between ferrets, and that it is lethal. What makes this news so bad is that ferrets are the best model for humans when it comes to flu response. What makes it not terrible is that a) the ferrets were infected with massive doses, b) it does not transmit easily, and c) it responds well to current antivirals such as zanamivir (Relenza) and others, if not to oseltamivir (Tamiflu). CIDRAP has a good write-up.

As I’ve said before, flu mutates all the time. I think it’s only a matter of time before this virus finds a way upgrade its current inefficient transmission to a much more efficient method. Especially given the fact that ordinary flu season is just getting started, and a fertile environment for such a mutation to occur would be in a host infected by, say, the Californian bovine strain during their job at a dairy farm who then catches regular flu. A perfect opportunity for the virus.

We’re not there yet—and I would love it if we never were. But do still keep an eye in your pets and on dead birds and observe sensible precautions. Just like fastening your seatbelt every time you’re in a car, it can’t hurt and it might help.