I’ve been watching avian influenza A(H7N9) virus cases in humans since they popped onto the radar in 2013 (it was among my first blogs, “H7N9 deaths” ).
So I’m confident when I say that 2018 has been a very unusual year for this avian influenza virus.
January is usually H7N9 season in full swing. We see peak spillover activity in China; the highest number of human cases of infection and (usually) illness in humans resulting from contact with infected chickens and other poultry often via live poultry markets (LPMs) in China. I say often, but for context, there have only been ~1,620 reported human cases and 620 deaths (38% of reported cases are fatal) across 5 years.
“Peak” spillover period may be represented by as few as 30 human cases to more than 200 in January. But in 2018 we’ve seen just 1 case reported this year.
I’ve hacked the graph below to highlight January in each of the years we’ve known H7N9 to spillover into humans; 2013 to 2018. 2018 is represented by the red, barely visible bar on the right-hand side. Hey Wave 6! Where are you?I’ve also highlighted Chinese New Year (CNY; green star). Before, during and after CNY is when the largest human migration on the planet occurs. But despite the many opportunities for enhanced transmission of H7N9, we have to date seen a decline after the CNY. H7N9 is thankfully not an efficiently transmitting Flu virus. It may never be. Or it may be tomorrow. So maybe the 2017/18 H7N9 season happened earlier? Nuh. No illnesses reported for December and just a handful from August to November.
Only a few months back we heard about H7N9 being the next big pandemic threat; a multi-billion dollar “sinister” virus that had concerned the Chinese agriculture industry, the World Health Organization, US health authorities and knowledgeable scientists alike [3,4,5,6,7,8]
But in 2018 I have to ask, where has H7N9 gone?
- H7N9 deaths
- FAO data from H7N9 update 24JAN2018
- This Sinister Virus Could Cause the World’s Next Flu Pandemic
- CDC Concerned by H7N9 Bird Flu’s Sudden Spread in China
- U.N.: H7N9 flu outbreak has cost $6.5 billion so far
- World must not miss early signals of any flu pandemic: WHO
- Summary of Influenza Risk Assessment Tool (IRAT) Results
- Influenza Risk Assessment Tool (IRAT)
- Novel influenza A viruses and pandemic threats
- Chinese New Year 2017: Largest migration of human beings in the world underway