Fatal infections with the rare COUG strain of Toxoplasma gondii have emerged in southern sea otters off the California coast. This PLoS One study, led by Karen Shapiro’s lab at UC Davis with our lab as collaborators, describes six additional deaths, most with the severe, widespread steatitis that defined the first cases.
The recently discovered parasite-infecting narnavirus was not detected in the sea otter isolates, arguing against a role in these deaths. Serotyping with dense granule peptides, an approach that grew out of our lab’s peptide-based serotyping work, can distinguish Type X, Type II and COUG strain infections, a step toward strain-specific diagnosis in wildlife.
Read the paper: Fatal Toxoplasma gondii COUG strain infections in southern sea otters (Enhydra lutris nereis): New insight on contributing factors and parasite serotyping. PLoS One 2025.