Bird flu viruses, beyond the well-known H5N1 strain, are increasingly concerning scientists due to their potential to mutate and pose a greater threat to human health. Researchers are closely monitoring other types of bird flu, particularly the H9N2 virus, which has demonstrated an ability to spread more efficiently among people and cause more severe disease, according to a study published in November by researchers in Hong Kong.

While H9N2 typically causes only mild symptoms in poultry, it can lead to more severe illness in humans, especially children, than seasonal influenza. Although there have been fewer than 200 reported cases of H9N2 in humans since 1998, the number of infections has been rising. China reported 29 human cases of H9N2 last year, compared with 11 in 2024.

Dr. Kelvin To, a clinical microbiologist who led the November study, suggests that these figures likely underestimate the true number of infections. He explained that many infected individuals are never tested, allowing the virus to spread undetected.

The concern stems from the virus's ability to acquire mutations that enhance its transmissibility and virulence in humans. This highlights the importance of ongoing surveillance and research to understand the evolving nature of avian influenza viruses and their potential impact on public health. The development of AI-powered surveillance systems could play a crucial role in rapidly identifying and tracking emerging viral threats. These systems can analyze vast amounts of data, including genomic sequences and epidemiological information, to predict potential outbreaks and inform public health interventions.

The rise of H9N2 cases underscores the need for increased vigilance and preparedness. Public health officials are urged to enhance surveillance efforts, improve diagnostic capabilities, and develop strategies to mitigate the spread of avian influenza viruses. The potential for these viruses to evolve and cause widespread human illness remains a significant concern, requiring a coordinated global response.