Echinococcus multilocularis in foxes and raccoon dogs: an increasing concern for Baltic countries

Abstract

BackgroundIn Europe, the life-cycle of Echinococcus multilocularis is predominantly sylvatic, involving red foxes (Vulpes vulpes) as the main definitive hosts and rodents such as muskrats and arvicolids as intermediate hosts. The parasite is the etiological agent of human alveolar echinococcosis, a malignant zoonotic disease caused by the accidental ingestion of eggs shed by definitive hosts in their faeces. The aims of this study were to investigate the prevalence of E. multilocularis in red foxes and raccoon dogs (Nyctereutes procyonoides) and to study the environmental factors favouring the perpetuation of the parasite in Latvia.MethodsA total of 538 red foxes and 407 raccoon dogs were collected across Latvia from 2010 to 2015. The sedimentation and counting technique was used for collecting E. multilocularis adult worms from fox and raccoon dog intestines. The morphological identification of the parasite was confirmed by molecular analysis.ResultsThe prevalence of E. multilocularis was significantly higher in foxes (17.1%; intensity of infection 1–7,050 worms) (P < 0.001) than in raccoon dogs (8.1%; intensity of infection 5–815 worms). In foxes, a significant positive correlation (r (10) = 0.7952, P = 0.001) was found between parasite prevalence and the intensity of infection. A positive relationship (R s = 0.900, n = 5, P = 0.037) between parasite prevalence and precipitation was also observed. In raccoon dogs, a significant negative relationship (F (1,8) = 9.412, P = 0.015) between animal density and parasite prevalence, and a significant positive relationship (F (1,8) = 7.869, P = 0.023) between parasite prevalence and agricultural land cover, were detected.ConclusionsThe results of this study confirm the red fox as the most important definitive host of E. multilocularis and, consequently, as the main target for control programmes in the Baltic countries. Raccoon dogs seem to play a secondary role in the life-cycle of E. multilocularis within the investigated European region.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1891-9) contains supplementary material, which is available to authorized users.

A comparative study of helminths of raccoon dogs (Nyctereutes procynoides) and red foxes (Vulpes vulpes) sharing the same territory

“…Prevalence in both final hosts were at low levels of 1.0% and 1.4%, respectively. This is comparably low compared to a study carried out in Latvia where the prevalence of E. multilocularis in raccoon dogs and red foxes amounted to 8.1% and 17.1%, respectively [37]. The first records of E. multilocularis in raccoon dogs in Germany were in two out of 74 (= 2.7%) animals originating from Uckermark and the bordering Barnim district.…”

Genetic tools in the management of invasive mammals: recent trends and future perspectives

“…Mammalian invasions in Europe are likely to have been responsible for the transport of pathogens responsible for salmonellosis, toxoplasmosis, and leptospirosis (Hulme ), and for the dissemination of the plague across continents via rodent introductions (Gage & Kosoy ). Genetic tools are becoming pivotal in disease management in wildlife (DeCandia et al ): PCR is currently used to verify morphological identification of pathogens and parasites (Bagrade et al ), and genetic tools can be used as detection methods when there are difficulties in recreating optimal cell growing conditions to test for prevalence levels (Heuser et al ).…”

Seroprevalence of Echinococcus spp. and Toxocara spp. in Invasive Non-native American Mink

“…In neighbouring countries, like Germany, Slovakia, and the Czech Republic, AE is also a serious epidemiological problem (Jorgensen et al 2008;Antolová et al 2014;Kolarova et al 2015). Knowledge about the reservoir of AE in wildlife focuses mainly on red fox (Vulpes vulpes) infection (Bagrade et al 2016;Karamon et al 2014;Miller et al 2016;Umhang et al 2016). Thus, it is thought that human AE is mainly present in areas with a large prevalence of infected red foxes (Nahorski et al 2013;Schweiger et al 2007).…”

“…However, other predators, including invasive non-native species, may participate in maintaining high abundances of the parasite in wildlife, e.g. the raccoon dog (Bagrade et al 2016;Machnicka-Rowiń ska et al 2002). Carnivorous mammals are hosts for both Echinococcus spp.…”

“…and Toxocara spp. parasites (Bagrade et al 2016;Holland 2017). Definitive hosts, such as red foxes, raccoon dogs, and wolves, shed parasite eggs into the environment and are important vectors in disease transmission, not only to other wild hosts, but also to humans who may accidentally ingest invasive forms of the parasites.…”