Parasite now infects beluga whales too

Toxoplasmosis is a disease caused by the parasite Toxoplasma gondii. The parasite infects most mammals but its primary host are cats and their feaces can carry millions of the parasite’s eggs. It also affects rodents who will lose their fear of cats, thus increasing the risk of being caught.

Toxoplasmosis is considered to be a major cause of death attributed to foodborne illness. Adults carry the Toxoplasma parasite, but very few have symptoms because the immune system usually keeps the parasite from causing illness. But infants are particulary at risk. Following maternal transmission. It can result in fetal death and abortion and in syndromes that include neurologic and neurocognitive deficits and chorioretinitis[1].
And now scientists have found[2] that the parasite infects beluga whales, too. The parasite has been found in more than 10 percent of beluga whales living off the Canadian Coast, in the Beaufort Sea. Local Inuits depend on the whales for meat, and the concern is that they might acquire an infection, either from preparing the meat or eating it undercooked.

Although the beluga whales do not appear to get ill by the infection, researchers are puzzling over how they acquired the parasite to begin with. It could be that more and more local people own cats, whose feces get washed into the water from the powdery Arctic soil. Or it could have something to do with climate change. As temperatures warm, perhaps the parasite is altering its ecological niche. While other marine animals have been shown to carry the infection before, this is the first time it has turned up in the Arctic.

What we have here then is another organism that has managed to cross a species barrier. We knew that the Influenza A virus already had infected whales.

[1] Jones et al: Congenital toxoplasmosis: a review in Obstetrical and Gynecological Survey - 2001 
 [2] Cat parasite found in western Arctic Beluga deemed infectious. Media release from the University of British Columbia - February 13, 2014

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