Habitat Characteristics as Potential Drivers of the Angiostrongylus daskalovi Infection in European Badger (Meles meles) Populations

Abstract

From 2016 to 2020, an investigation was carried out to identify the rate of Angiostrongylus spp. infections in European badgers in Hungary. During the study, the hearts and lungs of 50 animals were dissected in order to collect adult worms, the morphometrical characteristics of which were used for species identification. PCR amplification and an 18S rDNA-sequencing analysis were also carried out. Global and local spatial autocorrelation methods were used to detect high-rated and low-rated infected animal clusters. We conducted a binary logistic regression analysis along with hierarchical agglomerative clustering to determine the relation between selected biotic and abiotic variables, and the prevalence of an A. daskalovi infection. We found a high prevalence (72%) and moderate mean intensity (14.1) of Angiostrongylus sp. infection. Morphology and sequencing revealed that all animals were infected by A. daskalovi. The results of both spatial autocorrelations suggested that the spatial distribution of infected badgers was more spatially clustered than random. The results of an analysis of the correlation between habitat characteristics and infection showed that the infected animals could be associated with dry and open landscape habitats without extended and connected canopy. It is suggested that the territorial behaviour of badgers and the landscape-directed aggregation of potential intermediate hosts might be the drivers of an A. daskalovi infection.

Angiostrongylosis in Animals and Humans in Europe

“…Greater understanding of the biology, ecology and epidemiology of this genus is needed if the prospects of future spread and disease in Europe are to be evaluated and managed. A. daskalovi [8,[58][59][60][61], A. dujardini [11,91,92], A. vasorum [13,[30][31][32][33][34][35][36][37].…”

“…In the single detailed study of A. daskalovi in badger populations, in Hungary, burdens were higher in grassland than in mixed pasture-forest or wetlands [8], perhaps due to higher badger density and/or more favourable conditions for gastropod IH, species of which have not been confirmed. The parasite has been recorded from Southern and Eastern Europe [8], although it might be under-reported elsewhere. Although prevalence can be high, sample sizes in previous studies are low, and without repeated studies, no inference can be made on whether this species is stable in distribution or expanding.…”

“…Within-species variation in the diet of Angiostrongylus spp. DHs might account for spatial and demographic variations in the prevalence of infection, as observed for A. dujardini [11] and A. daskalovi [8]. Ingestion of gastropod IH is also implicated in the infection of DH and accidental hosts in zoological collections.…”

“…The DH of A. daskalovi is the European badger, although it has also been found in other native mustelids in Europe [8] as well as invasive American mink [58]. Reports of infection are few, but this could be confounded by uncertainty over the identification of metastrongyloid larvae in badger faeces, especially in the pre-genomic era [59].…”

“…Other Angiostrongylus spp. in carnivores and mustelids in Europe are Angiostrongylus chabaudi in cats [7] and Angiostrongylus daskalovi in badgers [8]. Similarly to A. vasorum, these exist in sylvatic cycles of unknown significance for host populations, whereas A. chabaudi can occasionally spill over to cause disease in domestic cats.…”