# 8374
In addition to announcing that the number of domestic birds culled in South Korea’s 2 month-old H5N8 outbreak has now exceeded 10 million (see Reuters South Korea culls over six percent of poultry to curb bird flu), Korea’s Ministry of Agriculture announced today that a dog from a bird flu affected farm in Chungcheongnam-do province has tested positive for antibodies to the H5N8 virus.
This marks the first time that evidence of an H5N8 infection has been found in a non-avian species, although the dog was reportedly asymptomatic.
Antibodies are generally detectable a couple of weeks after exposure, and are considered an indicator of past infection. First a report from Arirang News, then I’ll have more on the expanding host range of influenza viruses.
Dog infected with Avian Influenza
Updated: 2014-03-14 PM 4:30:10 (KST)Authorities have confirmed that a dog at a farm in Korea's Chungcheongnam-do province has been infected with the H5N8 strain of avian influenza.
Korea's agriculture ministry said Friday that the dog had tested positive for having antibodies against the H5 strain, meaning its immune system is battling the virus.
It's the first time in Korea that a mammal has come down with the AI virus.
Authorities say the dog became infected after eating an infected chicken at the farm.
Prior to this case, it was believed that the AI virus could only be transmitted among the same species.
It's raising concerns that humans could be susceptible to the H5N8 strain, but health authorities say that's very unlikely, although the farm's workers are being tested.
Despite the tendency of officials to make reassuring blanket statements whenever a new disease threat appears, one of the oft mentioned caveats in this blog is that viruses constantly evolve, as does our understanding of them. What might be reasonably stated as `true’ last week could easily require revision and amendment tomorrow.
And one of those areas of knowledge that seems to constantly evolve centers around the host range of various influenza viruses.
So the detection of H5N8 antibodies in canines, while potentially significant, isn’t completely unexpected. Over the past decade we’ve seen plenty of evidence of influenza’s cross-species promiscuity.
- Five years ago, few scientists would have put money on bats being a host species for influenza, yet in 2012 CDC researchers discovered a new flu strain in Guatemalan bats (see A New Flu Comes Up To Bat) and last year we saw in PLoS Pathogens: New World Bats Harbor Diverse Flu Strains.
- One of the surprises with the H5N1 avian flu virus was how readily it infected dogs and cats (see Study: Dogs And H5N1 and Israel: Cats Infected With H5N1 for background), when previously neither species had been consider particularly susceptible to influenza.
- The (formerly) pandemic H1N1 2009 flu virus was documented in turkeys, skunks, ferrets, cats, elephant seals and dogs.
- While in That Touch Of Mink Flu I wrote about 11 farms in Holstebro, Denmark that were reported to be infected with a variant of the human H3N2 virus.
- In 2012 we also saw mBio: A Mammalian Adapted H3N8 In Seals
- And just last week, we learned of a previously unknown subtype of Influenza C (see mBio: Characterizing A Novel Influenza C Virus In Bovines & Swine) prevalent in cows.
Today’s announcement simply means that scientists now have a little better understanding of this emerging H5N8 virus. We’ve moved beyond saying it can `only infect birds’, but the role or importance of mammals in the ecology of this virus is far from established.
What can be said, two months into this outbreak, is that in its present incarnation, the H5N8 virus is primarily a threat to avian species, as it doesn’t appear to readily sicken or infect mammals.
But as we learned yesterday (see EID Journal: Describing 3 Distinct H5N8 Reassortants In Korea) there are at least three genetically distinct versions of the virus in play on the Korean peninsula, and these will inevitably change, evolve, or reassort over time.
And as we know all too well . . . as viruses evolve, so can the threat they pose.
