#12,150
One of the worrying hallmarks of clade 2.3.4.4 H5 viruses has been its ability to reassort into new subtypes by borrowing genes from other avian flu viruses it encounters in the wild. While this can happen with any avian virus, H5N8 in particular has demonstrated an increased ability to reassort with other - mostly LPAI - viruses, and it continues to evolve and occasionally churn out viable novel subtypes.
In North America, during our brief 2014-15 epizootic, we saw novel strains of HPAI H5N1 and HPAI H5N2 emerge. While the H5N1 was pretty much a flash in the pan, HPAI H5N2 was a major contributor to outbreaks in several states.
We've seen hints that this sort of viral reassortment was going on in Europe, with reports (only in a handful of wild birds) of HPAI H5N5 - being found in Italy, The Netherlands, and Montenegro.
Today, however, we have a report of what is believed to be the first poultry outbreak of HPAI H5N5 in Europe - in Schleswig-Holstein - the northernmost of the 16 states of Germany,
First one (of many) media reports published in the past couple of hours, then I'll return with a bit more.
18,400 animals affected
Steinburg: virus H5N5 first time in poultry
In Schleswig-Holstein is the first time in a poultry population in Europe, a new type of bird flu virus has been found. The national reference laboratory at the Friedrich Loeffler Institute showed the highly pathogenic subtype H5N5 pathogen of animals from a holding in Steinburg.
Article updated: Monday, 01/23/2017 17:56
Kiel . From the avian influenza have been around 18 400 head affected in two attitudes operation. Some of the animals died already. For the rest of Gelfügepest Regulation was initiated in accordance with the killing on Monday. "This finding shows how dynamic the avian Done. The virus is still present and changing. This subtype also seems highly aggressive. In one location, more than half of the animals died within a short time, "said Agriculture Minister Robert Habeck. "In accordance with the avian influenza must be combated consistently. To reduce the risk of spreading as far as possible, the strict safeguards as kept indoors and biosecurity measures have continued. That's after more than two and a half months of avian influenza for all involved, especially for the poultry farmers and poultry keepers, a great burden. However, it is currently necessary to protect plants and animals as well as possible and to reduce the potential different pathways, "Habeck said.
(SNIP)
Virus H5N5 first time in Europe
To clarify the cause of the FLI will send at the request of the country, a team of experts for the epidemiological investigation. Here are all possible entry and distribution channels - including litter, food, trade and transport routes and operational management - examined. It is the first time that the pathogen of subtype H5N5 was detected in a poultry population in Europe. In current affairs, he has so far been found only in a few wild birds in Europe. He was discovered, according to the FLI in the Netherlands, Montenegro, Italy and Croatia. In Schleswig-Holstein, he has now been demonstrated in a Barnacle Goose from Brunsbüttel. The today gave the final subtyping of respective avian influenza detection.
(Continue . . .)
Two months ago, in EID Journal: HPAI A(H5Nx) Viruses With Altered H5 Receptor-Binding Specificity, we looked at a study that suggested the recent evolutionary changes to clade 2.3.4.4. H5 viruses may have increased its host range, and thereby its ability to spread.
Similarly, in Cell Host Microbe: Genesis, Evolution and Prevalence of HPAI H5N6 In China - another clade 2.3.4.4. H5 virus - we're seeing dozens of new H5N6 genotypes evolving in Asia.
All of which is a reminder that we aren't dealing with just one H5N8, one H5N6, or even one H7N9 virus. Each constantly spins off new versions of itself, either through antigenic drift, or antigenic shift (reassortment).
Most are evolutionary failures, unable to compete with the wild type versions already in circulation, and they fade away.
But every once in awhile - as we've seen with H5N6, H5N8, and H7N9 - theses viruses can spawn a better, more biologically `fit', flu virus, and they have the potential to take off.
The jury is still out on whether this novel H5N5 virus is a pretender or a contender, although FLI is calling it `highly aggressive'. We'll have to see where (or if) it turns up again.
But either way, at the rate things have been going, this isn't likely to be the last novel H5 virus we'll see come out of clade 2.3.4.4.
