Up until January of this year, H7N9 was an LPAI (low pathogenic avian influenza) virus in birds. That abruptly changed when a new, highly pathogenic strain emerged in Guangdong Province, one that infects both humans and poultry.
Now both HPAI and LPAI H7N9 can be found in China, with LPAI showing few, if any, symptoms in poultry while HPAI produces significant morbidity and mortality. Both remain highly pathogenic in humans, however.While it was initially hoped this new HPAI variant would be unable to compete with the far better established LPAI H7N9 virus, we've watched it steadily hopscotch its way north - likely via migratory birds - first to Hunan province, then to Hebei, Henan, and in late May, Shaanxi Province (see map).
Now we've a report from Inner Mongolia - which only first reported H7N9 in poultry a few weeks ago, and has now reported 3 human infections - that sounds suspiciously like HPAI H7N9.
Although high mortality is a hallmark of HPAI viruses, it will require lab tests to confirm the presence of the specific HA cleavage site mutation that is used to differentiate HPAI from LPAI.This (translated) report from China's Ministry of Agriculture.
Saihan District of Hohhot in Inner Mongolia occurred in poultry H7N9 flu epidemic has been effectively controlled at present
Date: 2017-06-08 16:12
May 31, Hohhot Saihan district veterinary department found in part in the monitoring of farms rearing laying hens appear suspected bird flu symptoms, the incidence of 59,556, 35,526 died.
June 4, Inner Mongolia Autonomous Region animal disease prevention and control center for the diagnosis of suspected bird flu. June 8, the National Avian Influenza Reference Laboratory confirmed the outbreaks as H7N9 flu.
After the outbreak, according to the relevant local prevention plans and technical specifications, adhere to the prevention and control law, science and prevention and control, really good job epidemic disposal, have been culling and safe disposal of 371,230 poultry. Currently, the outbreaks has been effectively controlled.
Hohhot is the capital city of Inner Mongolia, and is located 120 miles north and east of Ordos, where the first two human cases were reported from Inner Mongolia last week.
While HPAI H7N9's ultimate impact remains unclear, a month ago in Eurosurveillance: Biological Characterisation Of (HPAI) A(H7N9) Viruses In Humans, we learned that HPAI H7N9 virus retains the ability to infect both birds and humans, and in fact, appears to be potentially slightly more infectious in both than the LPAI version.A week ago, in EID Journal: 2 Expedited HPAI H7N9 Studies, we saw the first detailed reports on China's HPAI H7N9 human infections - and while their numbers (n=8) remain small, making it difficult to draw any conclusions - there are concerns this HP variant might be slightly more pathogenic in humans.
But whether LPAI or HPAI, H7N9 remains atop our list of novel flu viruses with pandemic potential.