No evidence of <i>Toxoplasma gondii</i> infection in urban and rural squirrels
Bibliographic record
Abstract
Abstract Wildlife in cities can act as reservoirs for parasites that can infect domestic pets and have implications for human health. For example, the Coccidian parasite Toxoplasma gondii can infect all mammalian species, with felids acting as the only definitive hosts. Rodents, such as squirrels, could play an important role in urban infection dynamics of T. gondii , as squirrels occur at higher densities in cities than in natural environments and regularly share their territories with cats. In urban and suburban areas squirrels can encounter infectious oocysts shed in cat feces in contaminated soil or in the food they eat. They are also preyed upon by cats making them a potentially important species for completing the T. gondii life cycle in cities. We hypothesized that due to increased exposure to cats, urban squirrels would be more susceptible to T. gondii infection relative to squirrels in more natural areas. We investigated this using molecular and serological methods on samples collected from American red squirrels ( Tamiasciurus hudsonicus ), eastern grey squirrels ( Sciurus carolinensis ), northern flying squirrels ( Glaucomys sabrinus ), and least chipmunks ( Tamias minimus ) in and around the city of Winnipeg, Manitoba, Canada. We tested a total of 230 tissue samples from 46 squirrels for T. gondii DNA using quantitative PCR and supplemented these data with analyses of 13 serum samples from grey squirrels ( Sciurus carolinensis ) testing for T. gondii antibodies by indirect ELISA. We found no evidence of T. gondii infection in any squirrel. This suggests that squirrels may not be important intermediate hosts of T. gondii in cities and do not need to be considered as sources of infection to cats.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".