Researchers at the University of Florida report discovering a dolphin infected with the highly pathogenic avian influenza virus.
- Researchers have discovered the case of a bottlenose dolphin infected with bird flu.
- High levels of H5N1 virus were detected in his brain.
- This is the first case of avian flu detected in a dolphin. In addition to birds, the virus has been spotted in ferrets, cows, cats, dogs, red foxes and even raccoons.
While the H5N1 strain of avian flu is rampant in the USA, scientists are alarmed by the spread of the virus, which mainly affects birds, to new species. After identifying the pathogen in cow’s milk, a new discovery turns out to be worrying.
A team from the University of Florida reports the case of a bottlenose dolphin infected with the highly pathogenic avian influenza virus in the journal Communications Biology.
Avian flu: a high viral load in the dolphin’s brain
A bottlenose dolphin (Tursiops truncatus) in distress was spotted near a dike in Dixie County (Florida) on March 29, 2022. Despite rescue attempts by those present, the animal died. To try to understand the causes of his death, researchers from the University of Florida transported the remains to their laboratory and carried out examinations.
In addition to neuronal necrosis and brain inflammation, tests revealed the significant presence of highly pathogenic avian influenza virus in the brain of the marine mammal. “It was confirmed to be the HPAI A (H5N1) virus of the HA 2.3.4.4b clade”specify the authors in their communicated.
On the other hand, the pathogen was not found in the lung tissues of the deceased cetacean.
The researchers specify that this is the first case of avian flu in a dolphin reported in the scientific literature.
Avian flu: a mysterious transmission to dolphins
Researchers sequenced the genomes of local birds and examined viruses from northeastern seal populations to try to understand the origin of the cetacean infection. Despite these numerous analyses, the question remains unanswered. “We still don’t know where the dolphin contracted the virus and further research needs to be carried out.”explains Professor Richard Webby, corresponding author of the article and director of the World Health Organization Collaborating Center for Studies on the Ecology of Influenza in Animals and Birds at St. Jude’s.
For the team, the discovery highlights “the importance of following appropriate biosafety protocols when working with stranded marine mammals and collecting brain tissue during post-mortem examinations of marine mammals, as high viral loads have been detected there”. Furthermore, she requests that “Screening for avian influenza viruses should be part of routine examinations in investigations of marine mammal strandings, particularly if the animal shows neurological signs”. These elements could ultimately help identify the incidence of the disease as well as the origin of transmission.
