Toxoplasma gondii microscopy and PCR detection results between July, 2020 and August, 2022 in greater Monterey Bay, CA

Toxoplasma gondii is a zoonotic parasite that can cause severe morbidity and mortality in warm-blooded animals, including marine mammals such as sea otters. Free-ranging cats can shed environmentally resistant T. gondii oocysts in their feces, which are transported to water bodies through rain-driven surface runoff. Certain genotypes of T. gondii were found in otters that died from toxoplasmosis, however, the source of these parasites has not been determined. Despite their large population sizes and ability to contribute to environmental oocyst contamination, there is limited knowledge on the frequency of oocyst shedding and genotypes of oocysts shed by free-ranging cats. We aimed to determine the presence of T. gondii oocyst shedding in free-ranging domestic cats in central coastal California and identify genotypes shed in feces. We utilized a longitudinal field study of four free-ranging cat colonies to assess oocyst fecal shedding prevalence using microscopy and molecular confirmatio..., Four colonies in Gilroy (Santa Clara County), Moss Landing (Monterey County), Aptos (Santa Cruz County), and Santa Cruz (Santa Cruz County) were sampled monthly between July 2020 and August 2022 (24 months). Sampling did not occur in February or March 2021 due to COVID-19 restrictions, and sampling occurred twice in April 2022 due to the low sample size (n = 5) during the first collection trip earlier that month. Three sites were located directly on the coastline, and one (Gilroy) was located inland (25.4 km from coast) in the Uvas-Llagas watershed, which drains into Monterey Bay. Samples with confirmed T. gondii are indicated with a 1 under the \"Toxoplasma confirmed\" column, while samples without T. gondii DNA are listed as 0. Samples that were not tested with PCR are indicated by \"NA\"., CSV file can be opened by R or other statistical software.