PubMed was down for a while. No idea how many political changes might have happened during the hiatus, so just mentioning that there is an untainted European alternative.
Europe’s alternative for PubMed for human and veterinary refs
It all comes back to route of infection and infectious dose with insects, in my opinion. If we are looking at mechanical transmission, as I understand is being discussed here, then the insects of interest would need to collectively carry sufficient viable viral load to susceptible animals in a place where it could be ingested, inhaled. etc. to produce infection. If it is a biting insect transmitting infectious virus via the bite, that is a different issue in some ways.
I'm not aware of any work showing insects ingesting and transmitting influenza via bites, so as mechanical vectors, I suppose it's possible, but a long way from demonstrated at this point.
I DO remain open to any mechanism that can transport sufficient viable virus from one farm to another in a form that can be ingested, i.e. breathed, swallowed, possibly blown into the eyes. I personally discount the "up the teat canal" as a likely natural route of infection, given an inability to reproduce it short of artificial cannulization. On-farm evidence shows that natural infection begins with mild respiratory signs, systemic symptoms and bulk tank viral loads, prior to any signs of clinical mastitis similar to those produced by viral infusions in the udder.
I could and maybe should write another column on my biases regarding between farm transmission. I'm not aerosol exclusive by any means! But other sources of contact spread need to be plausible - simple correlations don't equal causation, especially when each step in the transmission process have thresholds to meet to survive as viable alternatives. More later...
I know there was an induced mastitis study in nursing ferrets. The only real surprise for me was that systemic symptoms stayed low for the mothers for a while. The poor kits rapidly died, and given how H5N1 behaves in many members of carnivora that should not be a surprise. I gather they were wondering if HPAIs can cause mammary infection in a broad range of species to try to see if human mothers will need to use precautions if more human infections arise.
PubMed was down for a while. No idea how many political changes might have happened during the hiatus, so just mentioning that there is an untainted European alternative.
Europe’s alternative for PubMed for human and veterinary refs
https://europepmc.org/
In ACS Sensors:
ARTICLEFebruary 21, 2025
Capacitive Biosensor for Rapid Detection of Avian (H5N1) Influenza and E. coli in Aerosols
TRY AGAIN w URL:
https://pubs.acs.org/doi/10.1021/acssensors.4c03087
I just ran into a Canadian mention of specific INSECTS being considered as possible routes for transmission in
https://inspection.canada.ca/en/animal-health/terrestrial-animals/diseases/reportable/avian-influenza/animals-susceptible-h5n1-hpai
Sukie:
It all comes back to route of infection and infectious dose with insects, in my opinion. If we are looking at mechanical transmission, as I understand is being discussed here, then the insects of interest would need to collectively carry sufficient viable viral load to susceptible animals in a place where it could be ingested, inhaled. etc. to produce infection. If it is a biting insect transmitting infectious virus via the bite, that is a different issue in some ways.
I'm not aware of any work showing insects ingesting and transmitting influenza via bites, so as mechanical vectors, I suppose it's possible, but a long way from demonstrated at this point.
I DO remain open to any mechanism that can transport sufficient viable virus from one farm to another in a form that can be ingested, i.e. breathed, swallowed, possibly blown into the eyes. I personally discount the "up the teat canal" as a likely natural route of infection, given an inability to reproduce it short of artificial cannulization. On-farm evidence shows that natural infection begins with mild respiratory signs, systemic symptoms and bulk tank viral loads, prior to any signs of clinical mastitis similar to those produced by viral infusions in the udder.
I could and maybe should write another column on my biases regarding between farm transmission. I'm not aerosol exclusive by any means! But other sources of contact spread need to be plausible - simple correlations don't equal causation, especially when each step in the transmission process have thresholds to meet to survive as viable alternatives. More later...
John
I know there was an induced mastitis study in nursing ferrets. The only real surprise for me was that systemic symptoms stayed low for the mothers for a while. The poor kits rapidly died, and given how H5N1 behaves in many members of carnivora that should not be a surprise. I gather they were wondering if HPAIs can cause mammary infection in a broad range of species to try to see if human mothers will need to use precautions if more human infections arise.