Elephant Seals and Swine Flu

http://media-2.web.britannica.com/eb-media/96/99696-004-058EB9C8.jpg

This awkward looking fella' belongs to the species Mirounga angustirostris, or more commonly, the northern elephant seal.  Male elephant seals can grow up to 14 feet in length, and weigh over 5,000 lbs!  They inhabit the west coast of North America and can travel as far as Japan.  They are excellent swimmers for this is how they get most of their food; hunting fish and squid.  At extremes, elephant seals can dive to depths of 1,500 meters, and stay under water for a whopping two hours!  They can also travel over 12400 miles, annually. Though these giant marine mammals may seem tough, they are susceptible to many diseases.

In 2010, it was discovered that 28 elephant seals had traces of H1N1 anitbodies, suggesting that they were or had been infected with the virus while 2 were tested positive for the infection itself.  H1N1, you may better remember as swine flu, originated from pigs, but had emerged in humans in 2009 as a huge pandemic.  Elephant seals were tested at the beginning of 2010, and tested negative, but upon return from the sea in spring, tested positive.  The figure below maps out this phenomena.

Evidence of exposure to H1N1 in northern elephant seals off central California in 2010 to 2011

In the same study, two adult female elephant seals that tested positive for the virus had their paths tracked in 2008 and 2010.  The data collected can be seen in the figure below.

Tracking data from two adult female elephant seals that tested positive for H1N1 from 2008 and 2010

  This data shows that both seals took similar paths out to sea in 2008 and 2010.  Infection was detected in both seals within days of their return from sea suggesting that they were exposed before their return.  The question is; Where exactly were they and exposed and how?  Though this is not the first time that marine mammals have tested positive for strains of influenza, that question still remains unclear.




References

1. Tracey Goldstein, Ignacio Mena, Simon J. Anthony, Rafael Medina, Patrick W. Robinson, Denise J. Greig, Daniel P. Costa, W. Ian Lipkin, Adolfo Garcia-Sastre, Walter M. Boyce. Pandemic H1N1 Influenza Isolated from Free-Ranging Northern Elephant Seals in 2010 off the Central California Coast. PLoS ONE, 2013; 8 (5): e62259 DOI: 10.1371/journal.pone.0062259
2. 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
3. http://www.mnh.si.edu/mna/image_info.cfm?species_id=184
4. http://www.sciencedaily.com/releases/2014/04/140408213619.htm