Friday, 10 May 2013

H7N9 more transmissible than H5N1.

A comment in BMJ by Jane Parry stresses the use of closing live bird markets (LBMs)to halt human H7N9 cases and adds that this virus is more transmissible to/between humans than is H5N1 (45 human cases confirmed in China since 2001 vs H7N9's 132 but in only 5 weeks). 

I wonder how related this is to H7N9 being a low pathogenic avian influenza (LPAI) in birds compared to H5N1's highly pathogenic course in birds. H7N9 can, in theory, stealthily sweep through flocks without setting off veterinary alarm bells (human cases acting as the "sleeping" canary in the mine) whereas H5N1 triggers alarm and can be better controlled by early culling. 

So far 47,8000 samples from 1,000 farms and poultry markets have been been tested and only 39 have been H7N9 positive.