Emergence of Echinococcus multilocularis in dogs in Ontario: implications for public and wildlife health?

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1 Emergence of Echinococcus multilocularis in dogs in Ontario: implications for public and wildlife health? Andrew S. Peregrine 1, Jonathon Kotwa 1, Claire Jardine 1, Benoît Cuq 1, Nicola Mercer 2, Bruno Gottstein 3 1 Ontario Veterinary College, University of Guelph, Ontario 2 Wellington-Dufferin-Guelph Public Health, Fergus, Ontario 3 Institut für Parasitologie, Universität Bern, Bern, Switzerland

2 Talk outline Echinococcus multilocularis Disease in people E. multilocularis in Canada and the USA Recent emergence of parasite in Ontario dogs Why? Prognosis? Public and wildlife health concerns

3 Echinococcus multilocularis

4 Life cycle of Echinococcus multilocularis Alveolar echinococcosis J. Kotwa

5 Human infections Parasite typically develops in liver: Incubation period usually 5-15 years (Halkic and Gillet. 2004, N Engl J Med 351,4) 44-year old woman, 10-month history of intermittent discomfort in upper right abdomen

6 Survival rate in untreated people 10-year survival after diagnosis = 6-25% (Pawlowski et al 2001; Craig 2003) Non-resectable AE on long-term chemotherapy 10-year survival after diagnosis = 80-89% (Ammann et al 2000; Pawlowski et al 2001) Most pathogenic zoonosis in temperate and arctic regions of the Northern hemisphere (Kern et al 2003)

7 Approximate distribution of E. multilocularis in central North America AB SK MB (Kazacos 2003)

8 E. multilocularis in North America Prior to 2009, outside Alaska, no dog in USA/Canada described infected with E. multilocularis. Infection in cats: 2 farm cats in North Dakota (Leiby and Kritsky 1972). 3/131 cats in Saskatchewan (Wobeser 1971). In people, outside Alaska, infections acquired in USA/ Canada diagnosed in: one man from Manitoba (James and Boyd 1937). one woman from Minnesota (Gamble et al 1979). one person from Alberta (Massolo et al 2014).

9 2012 (ON case #1): Signalment 2-year old, neutered male, Boxer Clinical history presented to practice in southern Ontario (ON) 12-hour history inappetence, lethargy - reluctant to walk, sit, lie down cranial abdomen tense and painful

10 Exploratory laparotomy hemoabdomen originating from liver liver generalized, multifocal, white nodules

11 Liver space-occupying lesion had ruptured

12 Histology multi-loculated cystic structure + prominent inflammation

13 Histology multiple intra-luminal metacestodes

14 Histopathology multi-loculated cystic structure PAS stain

15 Molecular characterization 1. Sequence data for mitochondrial 12S rrna gene: 100% homologous to reference Echinococcus multilocularis gdna (Dinkel et al 1998) 2. RFLP analysis of mitochondrial NADH dehydrogenase 1 gene and 12S rrna gene: matched reference E. multilocularis gdna (Trachsel et al 2007) 3. Direct immunofluorescence with MAbG11-FITC: positive for E. multilocularis (Deplazes & Gottstein 1991) Final diagnosis: Hepatic alveolar echinococcosis

16 Life cycle of Echinococcus multilocularis Alveolar echinococcosis J. Kotwa

17 Life cycle of Echinococcus multilocularis Alveolar echinococcosis J. Kotwa

18 Where did the dog become infected?

19 2013 (ON case #2): Signalment 4-year old, spayed female, Boxer Clinical history presented to practice in southern Ontario for a wellness visit healthy masses palpated throughout abdomen fine needle aspirate of largest mass exploratory laparotomy

20 Sediment smear of aspirate

21 Exploratory laparotomy

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24 Where did the dog become infected?

25 Cases of canine alveolar echinococcosis

26 2015 (ON case #4): Signalment 4-year old, male, Boxer Clinical history June presented to practice in Guelph brief history lethargy, vomiting, abdominal pain radiographic detection of abdominal masses exploratory laparotomy: three large cavitated masses identified in the liver varying from cm in diameter.

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28 Bar = 5 cm

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30 Cases of canine alveolar echinococcosis

31 Cases of alveolar echinococcosis

32 Outcome for Ontario dogs with alveolar echinococcosis Case Surgical resection Albendazole treatment Survival after diagnosis Ontario #1 N/A N/A Euthanised at presentation Ontario #2 No 10 mg/kg/day Alive at 4 years Ontario #3 Yes complete? 10 mg/kg/day Loss to follow up Ontario #4 Yes - partial 10 mg/kg/day 4 weeks on, 4 weeks off Euthanised after 6 months Ontario #5 Yes-complete? 10 mg/kg/day Alive at 1 year

33 2016 Chipmunk September 2016: dog visited Christie Lake Conservation Area owner = veterinary technician Caught chipmunk Taken to local veterinary clinic as enlarged abdomen Radiograph taken not pregnant!

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37 Cases of alveolar echinococcosis

38 Current status From : 5 cases of alveolar echinococcosis in Ontario dogs 4 cases had lived entire life in Ontario 2 cases in Ontario non-human primates 1 case in Ontario chipmunk Previously, canine cases only reported in highly endemic areas! Reason for occurrence of cases?

39 Zoonotic threat? Intermediate stage is not infective to people

40 Zoonotic threat? Some dogs with intermediate stage in liver may also have patent intestinal infections. As soon as presumptive diagnosis, treat with praziquantel. As soon as confirmed diagnosis: Risk assessment & Testing of people: Antibody to E. multilocularis (Trotz-Williams et al 2016) All in contact people tested to date have tested negative

41 Public health Reports of cases of alveolar echinococcosis in people acquired in Ontario? Is it likely that there are human infections? Three cases of alveolar echinococcosis diagnosed in people in Alberta in past year. Where is the parasite in Ontario? Evaluation of wild canids across southern Ontario ( ) Wild rodent species infected? Prevalence of infection in wild rodents?

42 Dogs and public health Shedding eggs in feces = public health risk. What dogs are at greatest risk of an intestinal infection? Is it likely that infections in dogs are being missed? Intestinal infections? Liver lesions? Should a preventive program be recommended for dogs to prevent shedding of eggs? What is an effective prevention program? Monthly treatment with praziquantel

43 Conclusions Echinococcus multilocularis in dogs is an emerging issue in the Golden Horseshoe region of southern Ontario. Liver disease in dogs (alveolar echinococcosis) is most likely associated with ingestion of coyote/fox feces. Zoonotic concern associated with eggs shed in feces of dogs that hunt/ingest rodents. Changing reportable status of E. multilocularis in people would greatly help both medical and veterinary communities.

44 Acknowledgements Jessika Bronsoiler WestBrant Animal Hospital, Brantford, Ontario Barbara Deter Southgate Animal Hospital, Guelph, Ontario Jonathon Kotwa, Dorothee Bienzle, Robert Foster, Ian Barker, Alicia Skelding, Astrid Oscos-Snowball, Will Gow, Thomas Gibson, Brigitte Brisson, Brandon Plattner, Britta Knight, Christopher Pinard, Michelle Oblak, Doug Campbell, Erin Harkness, Hugh Cai, Patricia Taylor, Nicole Compo, Andrew Brooks, Marg Stalker Ontario Veterinary College/Animal Health Laboratory, University of Guelph, Guelph, Ontario Bruno Gottstein Institut für Parasitologie, Universität Bern, Bern, Switzerland

45 Acknowledgements

46 Questions?