Photo Credit Wikipedia
#16,198
While birds or pigs first come to mind when thinking about animal hosts for novel flu viruses in the wild, many other mammals are susceptible to infection (see Virology: Experimental Infection of Peridomestic Animals With Avian H7N9), including marine mammals like seals and whales.
These outbreaks likely happen more often than we know, but some recent documented examples include:
- In November of 2011, we saw a die off of seals in New England that was eventually tied to an H3N8 avian Flu Virus. In 2012's mBio: A Mammalian Adapted H3N8 In Seals, we saw further evidence that this virus had recently adapted to better bind to alpha 2,6 receptor cells, the type found in the human upper respiratory tract.
- In 2013 we saw a report (and a study) from UC Davis showing the human 2009 pandemic H1N1 virus had jumped to wild California Elephant Seals just one year after that virus emerged (see The 2009 H1N1 Virus Expands Its Host Range (Again)).
- And in 2017, during the HPAI H5N8 epizootic in Europe, that emerging subtype (clade 2.3.4.4.B) was found in Grey seals in the Baltic Sea (see EID Journal: Highly Pathogenic Avian Influenza A(H5N8) Virus in Gray Seals, Baltic Sea).
The biggest incident in recent memory, however, came in northern Europe (mostly Denmark and Germany & Sweden) in 2014, when as many as 3,000 harbor seals reportedly died from avian H10N7 (see Avian H10N7 Linked To Dead European Seals), prompting warnings to the public not to touch seals.
More recently - and of particular significance now that H5N8 has been demonstrated to be a zoonotic virus (see CDC Adds Zoonotic Avian A/H5N8 To IRAT List) - have been reports this year of species jumps of H5N8 to 4 seals (and a fox) in the UK, and to a seal in Sweden (see DEFRA: Epidemiological Report On 2020-21 Avian Flu & A Look Ahead To This Fall).
Today there are media reports from the DPA (Deutsche Presse-Agentur) on recent detections of HPAI H5N8 in a small number of dead seals found in the Schleswig-Holstein Wadden Sea. A link, and the opening paragraph, to a translated report posted on https://www.aerzteblatt.de/.
SEPTEMBER 20, 2021, 2:28 PMANIMALSdpa
Kiel. Avian influenza virus has been detected in three dead seals found in the Schleswig-Holstein Wadden Sea. First, several dead seals were examined at the Institute for Terrestrial and Aquatic Wildlife Research of the University of Veterinary Medicine Hannover in Büsum, said the Ministry of the Environment on Monday. The virus subtype H5N8 was detected in two animals. The Friedrich Loeffler Institute as the national reference laboratory has now confirmed the infection in three samples. According to initial investigations, there is a great similarity to the avian influenza viruses detected in wild birds in recent months.
I've been unable to find an official statement on the websites of the Institute for Terrestrial and Aquatic Wildlife Research of the University of Veterinary Medicine Hannover in Büsum or the Ministry of the Environment (BMU), but the story is getting a lot of play in the German language press.
It should be mentioned that it isn't clear if these seals died from H5N8, or simply died while infected with H5N8. The good news is, no new dead seals have been reported in the last week.
Although the HPAI H5 avian viruses commonly found in Europe have posed very little threat to humans, there are concerns that H5N8 - and its spun-off reassortments - may be moving towards becoming a more mammalian-adapted virus.
- the ". . . global spread of AIVs, particularly the H5N8 subtype, has become a major concern to poultry farming and wildlife security but, critically, also to global public health."
- And due to the ". . . long-distance migration of wild birds, the innate capacity for reassortment of AIVs, the increased human-type receptor binding capability, and the constant antigenic variation of HPAIVs the authors warned that it was imperative that " . . . the global spread and potential risk of H5N8 AIVs to poultry farming, avian wildlife, and global public health are not ignored."
