In a groundbreaking discovery, Florida scientists have reported the first documented case of highly pathogenic H5N1 avian influenza in a common bottlenose dolphin. The findings, published in the journal Communications Biology, highlight the potential for flu strains to infect a wide range of mammals, extending beyond the conventional sources of infection.

The incident dates back to March 29, 2022, when researchers from the University of Florida's Marine Animal Rescue Program received a distress call about a dolphin exhibiting clear signs of distress near Horseshoe Beach in North Florida. Unfortunately, by the time the researchers arrived, the dolphin had already passed away. The deceased dolphin was preserved on ice and brought to the university for an autopsy the following day.

During the post-mortem examination, the dolphin's brain and meninges showed indications of poor health and inflammation. Notably, tests for common infectious causes of brain inflammation yielded negative results, prompting the scientists to expand their search. Aware of bird die-offs in the area and outbreaks among other marine mammal populations, the researchers decided to screen for avian influenza.

Shockingly, testing revealed the presence of H5N1 in the dolphin's lungs and brain, making it the first reported case of highly pathogenic bird flu in a common bottlenose dolphin in North America. While other marine mammals such as harbor seals and other dolphin species have shown signs of HPAI recently, this discovery is significant as it highlights the vulnerability of cetaceans to this particular strain of avian influenza.

Although the current outbreaks of H5N1 in cows have been relatively mild, strains within the H5N1 lineage 2.3.4.4b have proven deadly to marine mammals. Interestingly, the genetic analysis did not indicate any known changes that would enhance transmission between mammals. However, the researchers emphasize that bird flu viruses mutate rapidly, raising concerns about the potential future adaptation of the virus to infect and spread among marine mammals.

The implications of A(H5N1) viruses adapting to dolphins and other cetaceans could be catastrophic for these populations, note the authors of the research paper. The ongoing investigation aims to identify the source of infection and provides insights into the ability of bird flu strains to cross species barriers into marine mammals.

This groundbreaking finding highlights the need for continued surveillance and research to better understand the complex dynamics between avian influenza and mammalian hosts. It serves as a reminder of the potential threats posed by zoonotic diseases and the importance of proactive measures to mitigate the risks and safeguard both animal and human health.

The researchers' pursuit of knowledge in this area will undoubtedly contribute to our understanding of zoonotic diseases and aid in the development of strategies to prevent future outbreaks and protect vulnerable populations.

Note: The information about the $20,000 reward offered after a dolphin was found shot dead in Louisiana is not mentioned in the provided text and thus not included in the generated news article.