Pearsonema plica in red foxes (Vulpes vulpes) from semi-arid areas of the Iberian Peninsula

• Published in: International journal for parasitology. Parasites and wildlife Vol. 19; pp. 78 - 83
• Main Authors: Arcenillas-Hernández, I., Ruiz de Ybáñez, M.R., Tizzani, P., Pérez-Cutillas, P., Martínez-Carrasco, C.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-12-2022; Elsevier
• Subjects: Earthworm; Moisture; Pearsonema plica; Red fox; Urinary bladder; Earthworm; Red fox; Pearsonema plica; Urinary bladder; Moisture
• ISSN: 2213-2244; 2213-2244
• DOI: 10.1016/j.ijppaw.2022.08.005

The nematode Pearsonema plica is a parasite infecting the urinary bladder of carnivores, with a described prevalence ranging from 1 to 90%. This parasite needs earthworms as intermediate host to complete its life cycle, being the red fox (Vulpes vulpes) a definitive host. The objective of this study was to analyse the prevalence and intensity of P. plica in the red fox population from the Region of Murcia (SE Spain), an area with semi-arid Mediterranean climate. The urinary bladder, kidneys and ureters of 167 red foxes were collected at necropsy, opened and observed to detect adult parasites. The influence of host variables (sex, age and body condition using Kidney Fat Index) and environmental variables (Normalized Difference Vegetation Index, Normalized Difference Moisture Index, Bare Soil Index, temperature, radiation, evapotranspiration, precipitation, Corine Land Cover categories and distance to urban areas) were evaluated using a Generalised Linear Model. Moran index was used to evaluate the parasite spatial aggregation. The prevalence found was very low (2.4%; median abundance 0 nematodes per fox; median intensity 7.5 nematodes per parasitized fox), which contrast with those described in other red fox populations in Europe. Environmental variables had a significant influence on the occurrence of P. plica, being NDMI, mean summer precipitation, percentage of forest and agricultural areas positively associated with P. plica abundance. The south-eastern Iberian Peninsula has a semi-arid climate that hinders the development of the life cycle of this nematode, which justifies its occurrence in specific areas where there are the suitable environmental conditions for the presence of earthworms. However, although semi-arid Mediterranean areas do not seem to be favourable carnivores to be parasitized by P. plica, we cannot underestimate the risk that exists in those areas where, either naturally or by human activity, there are environmental factors that favor the presence of this nematode.
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•Semiarid areas are not suitable for Pearsonema plica occurrence.•The low prevalence in the red fox is consistent with dry bioclimatic areas.•Moisture is critical for the development of the indirect life cycle of P. plica.•Humid microclimate sites in semiarid Mediterranean areas are transmission hotspots.