A rare and unusually potent strain of a parasite commonly found in cat feces killed four otters on the California coast, a finding researchers described Wednesday as unprecedented and potentially dangerous to humans and other animals.
Karen Shapiro, associate professor of pathology, microbiology and immunology at the University of California, Davis, described the preliminary findings in a press release as a “complete surprise” and said the rare strain of the parasite, known as Toxoplasma gondiihas never before been seen in sea otters or any other aquatic mammal or bird.
Shapiro and three co-authors from the university and the California Department of Fish and Wildlife published their research Wednesday in the journal Frontiers in Marine Science.
Melissa Miller-Henson of the Fish and Wildlife Department said in the release that she has studied toxoplasmosis in sea otters for 25 years and has never seen such severe lesions or large numbers of parasites.
“We are reporting our preliminary findings to warn others about this concerning condition,” she said. “Since Toxoplasma can infect any warm-blooded animal, it can also potentially cause disease in animals and humans that share the same environment or food sources, including clams, clams, oysters and crabs consumed raw or undercooked.”
Most cases of toxoplasmosis in healthy people go undetected, although it can cause serious illness in people with compromised immune systems, as well as miscarriages and other health problems for women who contract the parasite shortly before or during pregnancy, according to the Centers for Disease Control and Prevention .
It’s not clear how the rare strain of toxoplasma may affect humans, according to the release.
The four southern sea otters studied by the researchers were found from February 2020 to March 2022 in San Luis Obispo and Santa Cruz counties, according to the study. The researchers suggest that the animals may have contracted the parasites from rainwater runoff.
The type of toxoplasma found in their bodies, known as COUG, was first discovered in Canadian mountain lions in 1995. It’s not clear how the parasite got to California, but the release describes it as a recent arrival.