Prevalence of intestinal helminths of red foxes (Vulpes vulpes) in central Europe (Poland): a significant zoonotic threat

Abstract

BackgroundThe red fox (Vulpes vulpes) is widely distributed in the world; in central Europe, it is the most numerous wild species of the family Canidae. It can play the role of a definitive host for many intestinal parasites, including zoonotic helminths. Poland, with its geographical location (central Europe), is an interesting area for parasitological investigations of this species. The aim of this study was to evaluate and compare the prevalence of intestinal helminths in red foxes in different regions of Poland.MethodsIntestines of 473 red foxes from four different regions were examined using the sedimentation and counting technique (SCT). In addition, 344 samples of faeces were examined using flotation.ResultsOverall, intestinal helminths were found in 98.9% of red foxes. The average prevalence of detected parasites was as follows: Mesocestoides spp. (84.1%); hookworms (67.9%); Alaria alata (61.5%); Toxocara/Toxascaris (49.5%); Taenia spp. (42.5%); Echinococcus multilocularis (25.6%); and Trichuris vulpis (2.3%). The prevalence of the majority of parasite species was similar in each region. Significant differences between regions were observed in the case of E. multilocularis: a low prevalence in the south-western and northern regions (0% and 0.9%, respectively) and a high prevalence in the south-east and northeast (39.3% and 42.7%, respectively). In the case of A. alata, important differences were found between northern (96.5% and 93.7% in northern and northeast regions, respectively) and southern regions (15.2% and 24.7% for south-western and south-east regions, respectively). The percentage of positive samples obtained with coproscopic examination (except for Trichuris) was significantly lower than that obtained with SCT. Analysis of the prevalence estimated in individual regions with the use of both methods (flotation and SCT) showed a high correlation for all parasite species (except for Mesocestoides spp.). The flotation method also allowed us to detect the eggs of the lung nematode Eucoleus aerophilus (syn. Capillaria aerophila) (76.2% of positive foxes).ConclusionsThis study showed a very high percentage of red foxes infected with intestinal helminths in different parts of Poland. Depending on the location, some differences were observed regarding the prevalence of dangerous zoonotic parasites, which should be considered in the assessment of infection risk for humans.

Prevalence of intestinal nematodes of red foxes (Vulpes vulpes) in north-west Poland

“…Polish foxes in the present study. Similar prevalence has been demonstrated in studies in northern and southern Poland (1,30). However, another studies conducted in western and southern Poland showed a significantly lower prevalence of these nematodes (11-35%) (31,32,33).…”

“…The exceptions are the studies from the Czech Republic, where the prevalence of both species in foxes was equal (2).The parasite with the lowest prevalence in this study was Trichuris vulpis. This was supported by the results of Karamon et al(1) in Poland, who reported foxes infected with this nematode from 1.3% in south-east Poland to 4.4% in the north of the country. High prevalence have been reported only in southern Poland (64.4%)(50).…”

“…12.3% of tested foxes were found to be infected in Italy (27), 7.0% in Sweden (39), 5,5% in Switzerland (6), 4.8% in Ukraine (36) and 1.6% in Norway (38). However, Trichuris vulpis, which is localized in the large intestine, was very often not taken into consideration during post-mortem parasitological investigations because surveillances in foxes were often limited to the small intestine (1).…”

“…A number of studies suggest that the occurrence of geohelminths is associated with climate conditions (temperature, air and soil humidity, mean annual rainfall) that extend the lifespan of their free-living developmental stages (1,2,53,54,55). The region of north-west Poland is situated close to the sea, has substantial forest cover and a temperate climate, as well as a total annual rainfall of 500-800 mm and a mean annual temperature of 7-9 °C, as well as significant air humidity, indicating that this area supports the development of parasites.…”

Echinococcus Multilocularis and other Cestodes in Red Foxes (Vulpes Vulpes) of Northeast Italy, 2012-2018

“…Our prevalence of E. multilocularis is very similar to the 2.6% found in the bordering Slovenia in 2010 (15), but it is much lower than that recorded in endemic areas of Europe. There, E. multilocularis may reach in red foxes very high prevalence locally, such as 28.5% in Denmark (44), 25.6% in Poland (45), and in general a prevalence over 10% in eastern countries (reviewed in Oksanen (3)),…”