In @sciencemagazine: Based on the initial reports of highly pathogenic avian influenza H5N1 in dairy cows, one can hyphothesize that the main presentation is mastitis, with virus excretion into milk and cow-to-cow spread via milking machines. #vogelgriep
science.org/content/articl…

Thijs Kuiken Science Magazine Intriguing theory! How would you guess INITIAL transmission to cow udders occurred? (i.e. there had to be mechanism for H5N1 to reach the udders of Cow #1)

Are you imagining spillover into cows has occurred independently on MULTIPLE farms? (What does genomic data show?)

Euan Arnott Thijs Kuiken Science Magazine Lateral spread of mastitis through poorly disinfected milking equipment is a common occurrence. I’ve heard even of bTB spreading in this way. The puzzling bit is how a resp virus changes tropism so efficiently.

Helicobacterio 🇵🇸😥 Euan Arnott Science Magazine The switch of avian influenza virus from respiratory tract to mammary gland is not so surprising. Please recall that low pathogenic avian influenza virus infects intestinal epithelium, and highly pathogenic avian influenza virus infects respiratory epithelium. 1/2

Thijs Kuiken Euan Arnott Science Magazine In a way this is reassuring, since I think a virus with mammary glad tropism would be easy to control with some very basic on-farm biosecurity protocols.
Would such virus still maintain the ability to transmit through the respiratory pathway?
Thanks 😉

Helicobacterio 🇵🇸😥 Euan Arnott Science Magazine I don’t know. IF (if) H5N1 virus were to be maintained long-term in dairy cows via mammary transmission, which I do not consider to be likely because the transmission chain could easily be broken), … 1/2

Helicobacterio 🇵🇸😥 Euan Arnott Science Magazine … then it would be adapting both to efficient mammal-to-mammal transmission and to efficient mammary transmission. And I do not know whether these adaptations would be working against each other. 2/2

Thijs Kuiken Euan Arnott Science Magazine Well, time will tell…just keeping fingers crossed it does not jump into the massive pig production American sector!