Helen Branswell delivers some sobering news:
Swine flu viruses are missing at least two key features seen in all flu viruses present and past that transmit well among people and yet the viruses are spreading quite efficiently, two new studies suggest.
The research groups which produced the work differ slightly in their views of the degree to which the novel H1N1 virus is spreading, with one finding transmission isn’t yet as efficient as with human flu viruses while the other finding transmission rates are in lockstep with those of seasonal flu cousins.
There is no disputing the evidence, though – the virus is spreading around the globe, claiming at least 332 lives so far. And it is doing this without all the tools scientists would expect a flu virus to need to become a successful human pathogen.
“The take-home message is that a virus that does not have some of the features that we have previously recognized as hallmarks of adaptation of flu in humans was able to establish itself in humans and cause disease,” said Dr. Daniel Perez, an influenza virologist with the University of Maryland.
“Regardless of what the virus might do, I believe it is here to stay either as a whole virus or with some of its gene. It may be able to outcompete and-or co-circulate with seasonal flu strains.”