May 16, 2013

H1N1 in Elephant Seal Study

On the sunny California coast, known to be a playground for people and an important habitat zone for many marine species, researchers from the University of California Davis and rangers in the  Año Nuevo State Reserve have successfully monitored and tracked a colony of 72 Elephant seals over a period of 2 months. The (p)H1N1 virus was found in 2 when the second swabs from 42, 2 of which were transient females, were taken on their return from over a month at sea and antibodies specific to combating the (p)H1N1 strain were found in all of them.

Over the last 33 years it has been known that Influenza A Viruses have been able to spread from marine mammals to humans, cases dating back to the winter of 1979 when harbour seals were dying of acute pneumonia (found to be H4N5) which then affected and killed the people who were involved in the handling of the carcasses for disposal (shown to be H7N7); to the last in 2011 (H3N8). Multiple cases of other influenza A viruses have been found in other colonies of seals as well as in a stranded whale; over 900 other samples were tested between 2009 and 2011 from seal colonies along the Pacific from California to Alaska. Frozen archived samples have been sequenced and tested (a total of 129) from stranded seals that have been rescued and released were also tested after the results from these elephant seals came back. Of all these tests it has shown an increase since April 2010, of the antibodies by up to 40% in adults and

While this strain appears to be seal specific, as in it has adapted itself to target seals, it is still the H1N1 influenza A virus that has been found in avian, swine and human populations because comparisons of the gene sequence were compared against known sequences from 6 sources (5 swine and 1 avian), the reason they know this (p)H1N1 strain is seal specific is because the sequences were cultured on human liver slices and found they did not survive, or more correctly did not have enough of itself to replicate and adapt.

The importance of this to anyone handling marine mammals is obvious, personal protection is there to protect them from anything we may carry and to protect us from anything they may carry; this is clearly an opportunity for the H1N1 virus to become spread to humans if it is allowed to colonise and adapt so thorough cleaning of hands and equipment after treatment and release of the marine mammals is essential.


Goldstein T, Mena I, Anthony SJ, Medina R, Robinson PW, et al. (2013) Pandemic H1N1 Influenza Isolated from Free-Ranging Northern Elephant Seals in 2010 off the Central California Coast. PLoS ONE 8(5): e62259. doi:10.1371/journal.pone.0062259

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