Science | Cat Parasite mysteriously infects Beluga whales

An infectious form of Toxoplasma gondii, a parasite hosted by domestic cats, has spread to Beluga whales in the western Arctic. The infection is thought to have arisen through water or fish contaminated with cat faeces.

Initially identified in 2009, it is believed that the parasite has been infecting the belugas since 2006, and that it has spread to between 10 to 14 per cent of the population in the Canadian Beaufort Sea leading to health concerns for the Inuit people.  Notably, the Inuit are known for their love of whale meat. “Belugas are not only an integral part of Inuit culture and folklore, but also a major staple of the traditional diet. Hunters and community members are very concerned about food safety and security,” said Stephen Raverty, a veterinary pathologist with the B.C. Ministry of Agriculture and Lands’ Animal Health Centre.

Toxoplasma, a single-celled microbe, is capable of infecting nearly all warm blooded animals and completes its life cycle in cats. Michael Grigg, a molecular parasitologist with the US National Institutes of Health, adds that “A cat can excrete 100 million infectious Toxoplasma oocysts [seeds] and all it takes is for one of these oocysts to infect a warm-blooded vertebrate like ourselves.

Although human infection usually presents mild symptoms, taxoplasmosis is the chief cause of infectious blindness in humans, and potentialy fatal to an unborn fetus and the immunocomromised. Dr. Grigg added: “They are incredibly stable in the environment. You can put them in 100 per cent chlorine bleach and it won’t kill them. The only way to kill them is to freeze them, dessicate them or boil them.”

Nonetheless, these recent findings depict the first incidence of the Toxoplasma parasite in Arctic sea mammals. Scientists have remarked that this appearance may be due to warming climate conditions and the rise in local cat owners in the region. Dr. Grigg reiterates that climate change offers “an unprecedented opportunity for pathogens to shift to new environments and cause new disease. With increasing temperatures pathogens can persist and gain access to new hosts.”

The parasite has been observed in the hearts and diaphragms of the infected whale population. Still, it remains unclear what sort of effects the parasite’s presence will pronounce in the beluga. It is the continuous work of scientists, for the time being; to figure out what symptoms the belugas will exhibit.

 

Sofia Popov

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