Disease forecasts are like weather forecasts – we can’t predict the finer details of an outbreak, but we can identify emerging threats and prepare accordingly. The viruses that cause avian influenza pose a significant threat to global health, particularly the H5N1 subtype, which has caused nearly 900 human cases with a mortality rate about 20 times higher than the 1918 flu pandemic.
Researchers have studied the evolution of infectious diseases from an anthropological perspective, revealing patterns in how human behaviors shape the emergence and spread of diseases. The H5N1 virus is exhibiting a common pattern of stepwise invasion from animal to human populations, with incremental evolutionary changes that could allow it to transmit between people.
The key to slowing this process lies in understanding spillover, the potential for a disease-causing pathogen to jump from an animal host to humans. This requires the pathogen to have the right molecular “keys” compatible with the human host’s molecular “locks.” However, these locks often vary between species, making it challenging for the pathogen to infect new hosts.
The recent surge in animal outbreaks, including among birds and cattle, has led to a small number of human cases, mostly among poultry and dairy workers. Epidemiologists call this situation “viral chatter,” where human infections occur in sporadic outbreaks that may signal a larger pandemic if left unchecked.
To mitigate the risk of H5N1 becoming a common human infection, people can take basic measures such as better care of food animals, vaccination against seasonal influenza viruses, and improved nutrition and sanitation in impoverished populations. By understanding the evolutionary trajectories of infectious diseases and taking proactive steps, individuals and societies can reshape these trajectories for the better.
As experts warn, the emergence of H5N1 is a ticking time bomb that requires attention and action to prevent a global disaster.
Source: https://www.sciencealert.com/bird-flu-is-evolving-dangerously-but-we-can-prevent-a-disaster