Rapport 11- 2019 Status of Echinococcus multilocularis in Svalbard - Final Report to Svalbard Environmental protection Fund NORWEGIAN VETERINARY INTSTITUTE Status of Echinococcus multilocularis in Svalbard Preface This is the final report of the project “Status of Echinococcus multilocularis in Svalbard” 16/42. Funding for this project was allocated by the Svalbard Environmental Protection Foundation in the spring of 2016. The project was carried out by a team of researchers from the Norwegian Veterinary Institute and the Norwegian Polar Institute, who for the first time collaborated in this project. The Norwegian Veterinary Institute has contributed with expert knowledge on E. multilocularis, pathology, parasitological and molecular methods, and the Norwegian Polar Institute with specific expertise on Arctic foxes, sibling voles, E. multilocularis and environmental aspects. In addition, we have benefitted from working together with Fredrik Samuelsson, Svalbard guide with an MSc in Parasitology, whose local knowledge has greatly facilitated the sample collection. The results of our project were presented to locals at a seminar at the University Centre in Svalbard 19.11.2018. We gratefully acknowledge the Svalbard Environmental Protection Fund for supporting our project. We would also like to thank Paul Lutnæs/the Govenor of Svalbard, Rupert Krapp from the Norwegian Polar Institute and the Svalbard Vets for assisting in collecting samples for the project; Longyearbyens Hundeklubb, commercial dog sledging companies and private dog owners who kindly let us collect faecal samples from their dogs; arctic fox hunters who donated foxes for our study, and inhabitants in Longyearbyen who helped trapping sibling voles. In this project we have collaborated with Dr. Jenny Knapp from University of Bourgogne Franche-Comté, France to characterise the E. multilocularis isolates using microsatellite markers. This work was funded separately. The combined research activities have been presented in the scientific publication: Enemark HL, Woolsey ID, Fuglei E, Knapp J, Madslien K, Samuelsson F, Mørk T, Øines Ø, 2019. Status of Echinococcus multilocularis on the archipelago of Svalbard two decades after the first detection of the parasite. International Journal for Parasitology: Parasites and Wildlife XXXXX Oslo, 12 April 2019 Heidi L. Enemark Project Leader Collection of faecal samples from sledge dogs. Photo: Heidi L. Enemark Final Report to Svalbard Environmental Protection Fund 2 NORWEGIAN VETERINARY INTSTITUTE Contents Summary 1. Introduction 6 1.1. Background 6 1.2. Objectives 7 2. Materials and methods 8 2.1. Sample collection 8 2.1.1. Sibling voles 8 2.1.2. Arctic foxes 10 2.1.3. Faeces from domestic dogs 10 2.2. Laboratory analyses 11 3. Results and discussion 11 3.1. Sibling voles 11 3.2. Arctic foxes 12 3.3. Domestic dogs 13 3.4. Concluding remarks 14 4. References 15 Appendix a) Project information to dog owners b) Questionnaire Authors: ISSN 1890-3290 © Veterinærinstituttet 2019 Heidi L Enemark Eva Fuglei Funding: Ian D. Woolsey Svalbard Environmental Protection Fund Fredrik Samuelsson Torill Mørk Kristin Henriksen Knut Madslien Øivind Øines Photo front cover: Heidi L. Enemark Final Report to Svalbard Environmental Protection Fund 3 NORWEGIAN VETERINARY INTSTITUTE Contact information: Heidi L. Enemark, [email protected] Ian D. Woolsey, [email protected] Kristin Henriksen, [email protected] Knut Madslien, [email protected] Øivind Øines, [email protected] Norwegian Veterinary Institute Ullevålsveien 68 Pb 750 Sentrum NO-0106 Oslo Norway Torill Mørk, [email protected] Norwegian Veterinary Institute Stakkevollveien 23 NO-9010 Tromsø Norway Eva Fuglei, [email protected] Norwegian Polar Institute Fram Centre NO-9296 Tromsø Norway Fredrik Samuelsson [email protected] Independent consultant Final Report to Svalbard Environmental Protection Fund 4 NORWEGIAN VETERINARY INTSTITUTE Summary In this project we studied the prevalence of the zoonotic tapeworm Echinococcus multilocularis in final hosts, arctic foxes (Vulpes lagopus) and domestic dogs (Canis lupus familiaris), as well as in intermediate hosts, sibling voles (Microtus levis), in Svalbard, Norway. The overall aims were to reveal potential public health risks associated with the presence of E. multilocularis in Svalbard and uncover possible needs for interventions. In addition, presence of other gastro-intestinal parasites was analysed in dogs. E.multilocularis was recently ranked as the most import foodborne parasite in Europe due to its public health importance. The definitive hosts are infected through prey of infected rodents and shed eggs in their faeces without any signs of disease. Humans may become accidental intermediate hosts by ingestion of contaminated food/water, via environmental contamination or close contact with infected dogs. If left untreated, the mortality is close to 100% in humans. The samples (sibling voles (n=29) and faeces from dogs (n=89) and arctic foxes (n=304) were mainly collected between November 2014 and May 2017, but 38 “historical” samples from foxes collected between 2009 and 2013 were also included. To analyse for presence of E. multilocularis in the faecal samples, we used a highly sensitive molecular method (DNA fishing combined with real-time PCR detection), which is also used in the surveillance of E. multilocularis in mainland Norway to prove freedom of disease. This method can detect as little as one egg in 3 g of faeces, but it only tests positive if the faecal samples are collected during the patent phase of the infection i.e. when adult tapeworms are present in the intestines of infected final hosts. Faecal samples from dogs were also examined for presence of other gastrointestinal parasites using the McMaster method, and information about age, breed, housing, travel activity, deworming practices and health was collected for each dog in a questionnaire. With the assistance from the local inhabitants, sibling voles were trapped in and around Longyearbyen. These voles were later forwarded to the Veterinary Institute in Tromsø, where they were autopsied to establish possible liver changes caused by E. multilocularis. No E. multilocularis positive sibling voles were detected in our study. However, due to an insufficient sampling scheme many of the voles were decomposed or dried out and therefore not suited for autopsy. Consequently, we cannot rule out that we might have missed positive cases. Nevertheless, sibling voles were found all over Longyearbyen, and considering the ongoing climate changes they may spread/propagate even further. The overall prevalence of E. multilocularis in arctic foxes, 2014-2017, was 7.9%. In accordance with previous findings in Svalbard, all positive cases with one exception were detected within a radius of 60 km from Grumant, the core area of the sibling voles/E. multilocularis. A single E. multilocularis positive arctic fox was detected in the town of Longyearbyen, and even though no positive sibling voles were found, the theoretical conditions for the establishment of the E. multilocularis lifecycle may be present depending on the population densities of the hosts/intermediate hosts. An additional positive arctic fox was found on the island of Hopen, approximately 300 km from the core area of Grumant. These findings are worrying because they suggest that the infection may be transmitted to humans not only in the Grumant area, but also in other parts of Svalbard. The risk of infection outside the Grumant area is probably low though, as previous studies have clearly demonstrated that the risk of infection in foxes decreases with distance from Grumant. No dogs in the present investigation tested positive for E. multilocularis and low grade infections of other gastrointestinal parasites were only found in two dogs. Thus we could not perform a proper risk assessment. The results may indicate that the current deworming practices in Longyearbyen are sufficient. However, these results are based on a small sample size, and we therefore suggest that future studies should include a larger number of dogs, represent all age groups and preferably be based on serological detection of antibodies against E. multilocularis. Finally, surveillance of E. multilocularis in arctic foxes as well as in sibling voles is warranted to monitor further geographical spread of the infection in Svalbard. Final Report to Svalbard Environmental Protection Fund 5 NORWEGIAN VETERINARY INTSTITUTE 1. Introduction 1.1. Background Climate changes in the Arctic, result in rapid environmental and ecosystems changes (Post et al., 2009; Gilg et al., 2012), which in turn are expected to affect parasite transmission (Davidson et al., 2011). As a key predator in a simple and well-investigated terrestrial predator-prey-system (Ehrich et al., 2015), the arctic fox (Vulpes lagopus) is one of ten flagship species selected by the International Union for Conservation of Nature to represent and monitor consequences of climate changes on the tundra ecosystem (IUCN, 2009). Since changes in dynamics of parasitism in the Arctic may have direct influence on wildlife populations (Davidson et al., 2011) as well as humans, baseline knowledge on parasite diversity in this key predator can increase our knowledge on parasite-host-relationships, and thereby contribute to identify effects of climate changes on population dynamics in Svalbard. Ideally, this should be monitored regularly throughout several decades. The zoonotic (i.e.