Inadequate Management of a Highly Pathogenic Virus
20 July, 2024
The Oklahoma Department of Agriculture, USA, reports that samples collected from dairy cattle in April were recently tested and confirmed positive for the H5N1 avian influenza virus. The testing was apparently prompted by the USDA's compensation program for farms affected and damaged by the H5N1 virus. According to the official report, Oklahoma is the 13th state to report cases of avian influenza in dairy herds; however, the actual rank is lower since the samples were taken on April 19, when only eight states had reported the disease in dairy herds.
Continuous transmission between mammals increases the risk of the virus becoming more efficient at infecting humans and potentially transmitting from person to person. Although this risk is currently estimated to be low, it is increasing and cannot be ignored, necessitating heightened vigilance. This situation underscores the importance of effective cooperation between sectors involved in animal and human health.
At present, it appears that the USA is struggling to control avian influenza incidents in dairy herds. The extent of testing across various states suggests a "don't test, you won't find" approach. It is evident that the persistence of the virus in wild birds complicates efforts to control the spread of H5N1 in farm and domestic animals. Current policies are not effectively addressing the issue.
Viruses undergo evolutionary processes, and the evolving strains of H5N1 adapt to their environment, enhancing their spread and dominance over other variants. In dairy cows, the H5N1 virus appears to target the udder tissue. Given that cows have a higher body temperature (approximately 39°C) compared to humans, this adaptation theoretically does not favor human infection. However, the mammary glands in the udder contain receptors for both avian and human influenza viruses, potentially providing an adaptive advantage for human infection.
While the risk of human infection remains low, this risk is heightened by avian influenza incidents in dairy farms. The management of this outbreak has been inadequate, resulting from the authorities' failure to address the avian influenza outbreaks in the USA professionally and effectively.
The reason why the H5N1 is is not a big human health problem is because the virus is not that transmissible. It’s not because of our actions in response to this new situation.
