As the H5N1 avian influenza virus, commonly known as bird flu, continues to spread among cattle and other mammals, scientists are growing increasingly concerned about the potential for a spillover event that could have catastrophic consequences for humans.
In a recent study published in the CDC's Emerging Infectious Diseases journal, researchers found that cows infected with H5N1 experienced a mild illness characterized by a drop in milk production. However, cats that consumed raw milk from these cows developed severe systemic disease with high mortality. The study, which analyzed samples from farms in Kansas and Texas, also suggested cow-to-cow transmission of H5N1 and raised concerns about the consumption of raw milk as a potential transmission mechanism.
"The recurring nature of global H5N1 virus outbreaks and detection of spillover events in a broad host range is concerning and suggests increasing virus adaptation in mammals," the researchers wrote. They further emphasized the need for "surveillance of highly pathogenic avian influenza (HPAI) viruses in domestic production animals, including cattle, to elucidate influenza virus evolution and ecology and prevent cross-species transmission."
The H5N1 virus is already quite dangerous for humans. Since 2003, outbreaks of bird flu among poultry have resulted in 880 documented cases of presumed transmission from birds to humans, with about 50% of cases resulting in death. If the H5N1 virus gains the ability for sustained human-to-human transmission, we could be facing another deadly pandemic.
In light of these developments, pandemic experts are advocating for the use of wastewater surveillance as a tool for early detection and monitoring of the H5N1 virus. This method, which was used effectively during the Covid-19 pandemic, involves testing wastewater for the presence and levels of pathogens.
"We believe there is an urgent need to develop the capacity to rapidly detect and monitor the potential spillover of H5N1 into humans, including sustained human-to-human transmission," said a team of researchers who established New York City’s community-based wastewater surveillance for SARS-CoV-2. They argue that traditional public health surveillance approaches may not be sufficient for this task, and that wastewater surveillance could provide a more rapid and large-scale solution.
The researchers also highlighted the need for wastewater surveillance systems to distinguish between human and animal contributions of infectious material in sewer systems. They are currently developing genetic tests based on the H5N1 sequences that can be used for testing hospital wastewater in New York City.
As the researchers concluded, "more investment aimed at rapidly expanding the capabilities of wastewater surveillance is urgently needed for early detection and monitoring of a wider array of pathogens with pandemic potential."
More for you:
