Home > Health > Unusual parasite strain kills 4 California sea otters

Unusual parasite strain kills 4 California sea otters

An uncommon type of toxoplasma infection is posing a menace to marine animals within the state’s coastal area.

4 sea otters that were stranded in California died from an unusually extreme type of toxoplasmosis, in response to an examination from the California Division of Fish and Wildlife and the College of California, Davis (UC Davis). The illness is brought on by the microscopic parasite Toxoplasma gondii, an uncommon pressure of Toxoplasma that hasn’t been beforehand detected on the California coast.

The preliminary findings, printed within the journal Frontiers in Marine Science, a word that toxoplasmosis, which is probably going a current arrival on the California coast, is frequent in sea otters and may be deadly. This uncommon pressure seems to be particularly virulent and able to quickly kill wholesome grownup otters. Presently, no infections with the pressure have been reported in people, in response to an information launch from UC Davis.

“As a result of this parasite can infect people and different animals, we wish others to concentrate on our findings, rapidly acknowledge circumstances if they encounter them and take precautions to forestall an infection,” stated Melissa Miller of the California Division of Fish and Wildlife, and corresponding creator of the findings report, within the launch. “We encourage others to take additional precautions in the event that they observe infected systemic fats deposits in sea otters or different marine wildlife.”

Frequent parasite, uncommon end result

T gondii is a standard parasite hosted by wild and home cats and sheds of their feces. Though wholesome people hardly ever expertise signs, toxoplasmosis could cause miscarriages and neurological illness. Sea otters are particularly susceptible to Toxoplasma infection as a result of they dwell close to the shoreline the place they might be uncovered to the parasite’s eggs in rainwater runoff, they usually eat marine invertebrates that may focus the parasites.

The 4 sea otters described within the reported examination stranded between 2020 and 2022. All had steatitis, a situation with extreme irritation of physique fats. Extreme statistics is a really uncommon discovery in sea otters with toxoplasmosis, in response to investigators.

“The looks of this deadly kind of Toxoplasma in coastal California is regarding for two primary causes: First, due to potential inhabitants’ well-being impacts on a threatened species, and second, as a result of this parasite may additionally affect the well-being of different animals which are inclined to Toxoplasma an infection,” stated Devinn Sinnott of the UC Davis Faculty of Veterinary Medication, the examine’s coauthor, within the launch.

Microscopic examination of tissues confirmed Toxoplasma as the reason for dying for all 4 otters. Excessive numbers of parasites have been noticed all through every physique besides the mind, which is often one of many main organs affected in sea otters with deadly toxoplasmosis.

DNA testing recognized an uncommon pressure of Toxoplasma referred to as COUG in all 4 circumstances. This pressure was first present in 1995 in Canadian mountain lions throughout surveillance after a close-by outbreak amongst people, however, the pressure of Toxoplasma chargeable for the outbreak was by no means reported. Detection of COUG in sea otters was a shock, in response to Karen Shapiro of the UC Davis Faculty of Veterinary Medication, a senior creator on the examination. “The COUG genotype has by no means earlier than been described in sea otters, nor anyplace within the California coastal surroundings or in every other aquatic mammal or fowl,” stated Shapiro, within the launch.

Sea otters beneath menace

All 4 otters were stranded in periods of excessive coastal rainfall, which suggests they might have been uncovered to Toxoplasma eggs by way of storm runoff. Though 3 of those otters stranded close to one another, it’s unclear whether or not they have been all contaminated in the identical location. How this uncommon pressure would possibly affect people or different animals can also be unknown.

“I’ve studied Toxoplasma infections in sea otters for 25 years, and I’ve by no means seen such extreme lesions or excessive parasite numbers,” Miller added. “We’re reporting our preliminary findings to alert others about this regarding situation. Since Toxoplasma can infect any warm-blooded animal, it may additionally doubtlessly trigger illness in animals and people that share the identical surroundings or meals sources, together with mussels, clams, oysters, and crabs which are consumed uncooked or undercooked.”

Investigators are famous that with elevated surveillance, the COUG pressure could also be recognized in different animals. “We nonetheless have a lot to study,” stated Sinnott. “Bigger-scale research are wanted to grasp the potential influence of an infection by the COUG Toxoplasma pressure on sea otter populations, how geographically dispersed it’s, how it’s being launched into the ocean and what different animals is perhaps affected.”


Sea otters killed by uncommon parasite pressure. Information launch. UC Davis. March 23, 2023. Accessed March 24, 2023. https://www.ucdavis.edu/well being/information/sea-otters-killed-unusual-parasite-strain

Leave a Reply