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Elephant seal colony struggles after bird flu deaths
Scientists only expect a third of the usual number of elephant seals to return.
More than 17,000 elephant seals died during the H5N1 outbreak.

An elephant seal colony in Argentina is continuing to decline, following the devastating effects of last year’s avian influenza outbreak.

The colony, which breeds in Pen
ínsula Valdés, had over 17,000 elephant seals die from the highly pathogenic avian influenza in 2023. This included approximately 97 per cent of the seals’ pups.

This year, scientists only expect a third of the usual number of elephant seals to return.

A new study, conducted by the UC Davis School of Veterinary Medicine and the National Institute of Agricultural Technology in Argentina, has now explored the spread of H5N1 among marine animals such as elephant seals.

The researchers have found evidence of mammal-to-mammal transmission of H5N1, with the influenza spreading efficiently among marine mammals. They believe the outbreak among the elephant seals could be a stepping stone to the first transnational spread of the virus in the species as it reached five countries across southern South America.

In an unprecedented discovery, a genomic analysis uncovered that, once it entered South America, the virus evolved into separate avian and marine mammal clades.

Agustina Rimondi, a virologist and the study’s co-leading author, said: “This virus is capable of adapting to marine mammal species, as we can see from the mutations that are consistently found in the viruses belonging to this clade.

“Very importantly, our study also shows that H5 marine mammal viruses are able to jump back to birds, highlighting the need for increased surveillance and research cooperation in the region.”

The effects of the H5N1 outbreak are still being seen in the elephant seal colony, with the Wildlife Conservation Society of Argentina  (WCS Argentina) saying that it has reversed decades of conservation efforts.

The group says that more than half of the colony’s reproductive population of elephant seals died during the epidemic. Its data reveals that most of the adult males and many of the most experienced and fertile females have not returned.

WCS Argentina believes it could take decades for the numbers to return to the 2022 population size.

There have been no confirmed cases of H5N1 among the elephant seals this breeding season. However, scientists are still seeking answers to the causes of last year’s outbreak.

Scientists still don’t know whether the virus was transmitted by aerosol, saliva, faeces or other means. It is also unclear whether the surviving animals have developed a resistance via protective antibodies.

The researchers believe that continued investigation and monitoring will be vital to understanding how it evolves. They state that the virus’ adaptability could see it have global consequences for human health, ecosystems, and wildlife conservation.

The full study can be found in the journal Nature Communications.

Image © Shutterstock

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Antibiotic Amnesty survey opens

News Story 1
 The Responsible Use of Medicines Alliance - Companion Animal and Equine (RUMA - CA&E) has launched a survey which seeks to measure the success of this year's Antibiotic Amnesty campaign.

Its results will help the group to calculate how many unused or out-of-date antibiotics were returned as part of the campaign throughout November. Practices are also asked how they engaged with clients to raise awareness of the issue.

Participating practices can enter a prize draw to win up to 100 in vouchers for taking part. Further prizes from BSAVA and Webinar Vet will be available for practices with the best input.

The survey takes a few minutes to complete and will be running throughout December. It can be accessed via this link

Click here for more...
News Shorts
Avian flu confirmed at premises in Cornwall

A case of highly pathogenic avian influenza H5N1 has been detected in commercial poultry at a premises near Rosudgeon, Cornwall.

All poultry on the infected site will be humanely culled, and a 3km protection zone and 10km surveillance zone have been put in place. Poultry and other captive birds in the 3km protection zone must be housed.

The case is the second avian flu case confirmed in commercial poultry this month. The H5N5 strain was detected in a premises near Hornsea, East Riding of Yorkshire, in early November. Before then, the disease had not been confirmed in captive birds in England since February.

The UK chief veterinary officer has urged bird keepers to remain alert and practise robust biosecurity.

A map of the disease control zones can be found here.