Photo Credit – FAO
Admittedly, with only 1 human notch on its belt (see Sichuan China: 1st Known Human Infection With H5N6 Avian Flu), the H5N6 avian flu virus which emerged last April may seem an almost trivial public health hazard – particularly when compared to the recent exploits of MERS, H7N9, and Ebola.
But big epidemics from little viruses grow, and the same could have been said about MERS, H7N9, and even Ebola not so long ago.
After making an initial appearance in south central China last spring, the reassorted H5 virus laid low over the summer, but over the past 30 days has made multiple appearances in Vietnam and in China.
- On Monday, in China: H5N6 Outbreak In Heilongjiang Poultry, we looked at a large outbreak in China’s northernmost province, killing more than 18,000 geese.
- Last week, in Vietnam Orders Intensified H5N6 Surveillance, we saw reports of that country’s 3rd outbreak of the summer, along with news that hospitals in Lao Cai province had been asked to send respiratory samples from any acute pneumonia or respiratory cases to Hanoi for testing.
Of note, the distance between Heilongjiang Province, China and Lao Cai Province in Vietnam is more than 2000 miles, suggesting this upstart virus is conquering new territory rapidly.
Today the FAO EMPRES site is reporting two new outbreaks of H5N6 in Vietnamese poultry.
Whether or not H5N6 ever poses a serious public health threat, is has all of the earmarks of another expensive, and difficult to control poultry disease. And it is just the latest in a series of worrisome influenza reassortants coming out of Eastern Asia.
Last January, H5N8 emerged in Korean wild birds and poultry and spread rapidly (including briefly to Japan), resulting in the culling of more than 10 million birds.
These viruses have a habit of `mixing and matching’ gene segments between themselves, producing new clades – and sometimes even new subtypes – of influenza. At least three clades of H5N8 have already been detected.
While less is known about the evolution of the H5N6 virus, the longer it remains in circulation, the more opportunities it will have to reassort with other avian viruses (notably H9N2).
All of which makes H5N6 a virus worth keeping tabs on.