Evidence map›Paper›PMID 38263195›Full record

ArticleParasites & vectors2024

Drivers of infection with Toxoplasma gondii genotype type II in Eurasian red squirrels (Sciurus vulgaris).

Sara R Wijburg, Margriet G E Montizaan, Marja J L Kik, Maike Joeres, Garance Cardron, Christine Luttermann, Miriam Maas, Pavlo Maksimov, Marieke Opsteegh, Gereon Schares

Open access · goldAbstract read
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Article in Parasites & vectors, 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed, 0 citations in OpenAlex.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

10 authors at 3 institutions in 2 countries.

Sara R WijburgCentre for Infectious Disease Control, Centre for Zoonoses and Environmental Microbiology, National Institute for Public Health and the Environment (RIVM), Antonie Van Leeuwenhoeklaan 9, 1, 3720 BA, Bilthoven, The Netherlands.
Margriet G E MontizaanDutch Wildlife Health Centre, Faculty of Veterinary Medicine, University of Utrecht, Yalelaan 1, 3584 CL, Utrecht, The Netherlands.
Marja J L KikDutch Wildlife Health Centre, Faculty of Veterinary Medicine, University of Utrecht, Yalelaan 1, 3584 CL, Utrecht, The Netherlands.
Maike JoeresInstitute of Epidemiology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493, Greifswald - Insel Riems, Germany.
Garance CardronInstitute of Epidemiology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493, Greifswald - Insel Riems, Germany.
Christine LuttermannInstitute of Immunology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493, Greifswald - Insel Riems, Germany.
Miriam MaasCentre for Infectious Disease Control, Centre for Zoonoses and Environmental Microbiology, National Institute for Public Health and the Environment (RIVM), Antonie Van Leeuwenhoeklaan 9, 1, 3720 BA, Bilthoven, The Netherlands.
Pavlo MaksimovInstitute of Epidemiology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493, Greifswald - Insel Riems, Germany.
Marieke OpsteeghCentre for Infectious Disease Control, Centre for Zoonoses and Environmental Microbiology, National Institute for Public Health and the Environment (RIVM), Antonie Van Leeuwenhoeklaan 9, 1, 3720 BA, Bilthoven, The Netherlands.
Gereon ScharesInstitute of Epidemiology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493, Greifswald - Insel Riems, Germany. gereon.schares@fli.de.
Friedrich-Loeffler-Institut · DENational Institute for Public Health and the Environment · NLUniversity Medical Center Utrecht · NL

Funding

European Union's Horizon 2020 TOXOSOURCES, grant agreement No 773830
6 · The paper itself

Abstract

backgroundIn September 2014, there was sudden upsurge in the number of Eurasian red squirrels (Sciurus vulgaris) found dead in the Netherlands. High infection levels with the parasite Toxoplasma gondii were demonstrated, but it was unclear what had caused this increase in cases of fatal toxoplasmosis. In the present study, we aimed to gain more knowledge on the pathology and prevalence of T. gondii infections in Eurasian red squirrels in the Netherlands, on the T. gondii genotypes present, and on the determinants of the spatiotemporal variability in these T. gondii infections. The presence of the closely related parasite Hammondia hammondi was also determined.

methodsEurasian red squirrels that were found dead in the wild or that had died in wildlife rescue centres in the Netherlands over a period of seven years (2014-2020) were examined. Quantitative real-time polymerase chain reaction was conducted to analyse tissue samples for the presence of T. gondii and H. hammondi DNA. Toxoplasma gondii-positive samples were subjected to microsatellite typing and cluster analysis. A mixed logistic regression was used to identify climatic and other environmental predictors of T. gondii infection in the squirrels.

resultsA total of 178 squirrels were examined (49/178 T. gondii positive, 5/178 H. hammondi positive). Inflammation of multiple organs was the cause of death in 29 squirrels, of which 24 were also T. gondii polymerase chain reaction positive. Toxoplasma gondii infection was positively associated with pneumonia and hepatitis. Microsatellite typing revealed only T. gondii type II alleles. Toxoplasma gondii infection rates showed a positive correlation with the number of days of heavy rainfall in the previous 12 months. Conversely, they showed a negative association with the number of hot days within the 2-week period preceding the sampling date, as well as with the percentage of deciduous forest cover at the sampling site.

conclusionsToxoplasma gondii infection in the squirrels appeared to pose a significant risk of acute mortality. The T. gondii genotype detected in this study is commonly found across Europe. The reasons for the unusually high infection rates and severe symptoms of these squirrels from the Netherlands remain unclear. The prevalence of T. gondii in the deceased squirrels was linked to specific environmental factors. However, whether the increase in the number of dead squirrels indicated a higher environmental contamination with T. gondii oocysts has yet to be established.

Indexed as

Rodent DiseasesSarcocystidaeToxoplasmaToxoplasmosisAnimalsGenotypeSciuridaeMicrosatellite typingMonitoringOocystParasitePopulation structureSentinelSquirrelToxoplasmosisZoonoses

Identifiers

PMID38263195
PMCPMC10804655
OpenAlexW4391133656

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LicenceCC BY
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.