Echinococcus multilocularis in Denmark 2012–2015: high local prevalence in red foxes

Abstract

In Western Europe, the Echinococcus multilocularis lifecycle is predominantly sylvatic, typically involving red foxes (Vulpes vulpes) as the main definitive hosts with Microtus spp. and Arvicola spp. as intermediate hosts. During a 4-year surveillance study (2012-2015), Danish red foxes and raccoon dogs (n = 1345) were examined for E. multilocularis. Moreover, 134 insectivores and rodents collected in South Jutland during spring and summer 2016 were examined for the presence of metacestodes. The sedimentation and counting technique and molecular typing were used to identify E. multilocularis infections in the carnivores, while the rodent livers were examined macro- and microscopically for parasite lesions. Following morphological identification of E. multilocularis adult worms, the identity was verified by sequence analysis of the 12S rRNA gene in most cases (n = 13). Echinococcus multilocularis infection was demonstrated in 19 red foxes (Vulpes vulpes) originating from only two specific areas of South Jutland, namely Højer and Grindsted, and in two raccoon dogs (Nyctereutes procyonoides), originating from Højer. In Højer, 28.5% (CI 95% 11.7-45.3) of the examined red foxes were E. multilocularis positive per year. Moreover, positive red foxes were identified each year from 2012 to 2015, while E. multilocularis positive red foxes were only identified in Grindsted in 2013 (4.0%) and 2014 (6.4%). In contrast, all collected rodents were negative for E. multilocularis. We conclude that E. multilocularis is locally endemic in South Jutland with a high local prevalence in Højer.

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 Slovenia in 2010 [ 17 ], but it is much lower than that recorded in endemic areas of Europe. There, E. multilocularis may reach a very high prevalence in red foxes locally, such as 28.5% in Denmark [ 59 ] and 25.6% in Poland [ 60 ], and in general a prevalence > 10% in eastern countries (reviewed in Oksanen [ 3 ]), where human cases are annually reported [ 61 ]. In such areas, due to the high prevalence of the parasite, the positive predictive value of diagnostic tests will probably be much higher than in our territory, in which E. multilocularis seems instead a patchy and rare pathogen with very low prevalence.…”

Detection ofEchinococcusspp. and other taeniid species in lettuces and berries: two international multicenter studies from the MEmE project

“…In contrast to Poland, 4% of lettuce samples (n=50) and 1.8% of strawberry samples (n=56) from Denmark were found to be contaminated by E. multilocularis . Interestingly, such percentages has not been found from an area where high local prevalence of E. multilocularis in foxes have been previously described (Petersen et al, 2018), reflecting the patchy distribution of E. multilocularis at a local scale. This highlights the difficulty in drawing definitive conclusions regarding the different levels of food contamination between countries, especially due to the relatively low number of samples collected in each area.…”

First report of infection with metacestode stages of Echinococcus multilocularis in a kulan (Equus hemionus kulan) from Slovakia

“…As part of the sylvatic life cycle of Echinococcus multilocularis , red foxes ( Vulpes vulpes ) and raccoon dogs ( Nyctereutes procyonoides ) act as main final hosts, while rodent species as e.g., Microtus spp. serve as predominant intermediate hosts in Europe ( Petersen et al, 2018 ). Nevertheless, other carnivores are able to function as final hosts also, e.g., dogs ( Canis lupus familiaris ), wolves ( Canis lupus ) and golden jackals ( Canis aureus ) ( Citterio et al, 2021 ).…”