Over the last few years, the world has witnessed a natural catastrophe ultimately resulting in the death of hundreds of millions wild and domesticated birds caused by an avian influenza H5N1 virus (clade 2.3.4.4b). In addition this virus is infecting and killing thousands of wild mammals, and is also spreading to pets1. The recent detection of HPAI infection in cattle was completely unexpected, as for long, the prevailing assumption was that cattle were not susceptible to infection with the influenza A virus2. As well as our totally incorrect assumption, we now have a huge problem to manage which has public health an ethical ramifications. To date 51 cattle farms in 9 states have been found to be infected with the H5N1 strain of avian influenza3 which has also been found in wastewater from nine Texas cities4. This same strain has caused the death or culling of approximately 450 mln poultry between 2022 and 2023. Veterinary regulations in WOAH member countries require a culling policy on any poultry premise which is diagnosed as infected and prohibit any movement of biological material from that premise to ensure it does not enter the food chain. In addition, vaccination is prohibited unless the farmer can prove there is no circulation of virus, and if this becomes the case – the flock is culled. On the contrary, restrictions which have been put in place for the recently infected cattle farms are orders of magnitude less stringent. Dairy cattle must test negative for Influenza A virus before movement; if they test positive, movement is prohibited, and retesting is done after 30 days5. Moreover, the guidelines for the disposal and destruction of milk from infected cows are not compulsory but rather recommendatory. The guidelines stipulate that if milk from cows testing positive for the virus cannot be discarded and is intended for consumption by calves or other farm animals, it is highly recommended to heat treat the milk to inactivate harmful pathogens, including influenza viruses, prior to feeding5. This approach of two weights and two measures raises issues about ethics and coherence when controlling animal diseases. Namely, about the latter it is unclear and rather unimaginable by the public opinion why on health grounds birds should be culled, minks should be culled and a potentially enormous reservoir of H5N1 such as cattle should not also given the growing public health implications of this infection. As to the ethics component of controlling animal diseases, in the face of a disease which resembles more a panzootic that an epidemic – should we review our approach to controlling HPAI H5N1 through a more manageable vaccination approach or should we continue to cull indefinitely our farm animals as other species get infected, even just for the sake of mere coherence?

CAPUA Ilaria;  FANELLI Angela; 

2024-11-12

AAAS

JRC138237

https://publications.jrc.ec.europa.eu/repository/handle/JRC138237,   

https://doi.org/10.1126/science.adr5181 (online),