Nissen, Sofie5; Nguyen, Lan Anh Thi4; Dalsgaard, Anders6; Thamsborg, Stig Milan7; Johansen, Maria Vang7
1 Parasitology and Aquatic Diseases, Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, Københavns Universitet2 Food Safety and Zoonoses, Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, Københavns Universitet3 Section of Parasitology, Health and Development, Department of Veterinary Disease Biology, Faculty of Life Sciences, Københavns Universitet4 National Institute for Veterinary Research5 Section of Parasitology, Health and Development, Department of Veterinary Disease Biology, Faculty of Life Sciences, Københavns Universitet6 Food Safety and Zoonoses, Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, Københavns Universitet7 Parasitology and Aquatic Diseases, Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, Københavns Universitet
Fishborne zoonotic trematodes (FZT) are highly prevalent in Southeast Asia. Recent studies on the role of domestic animals in the transmission of FZT in Northern Vietnam found that dogs, mainly infected with Haplorchis pumilio, contributed widely to the transmission of FZT. On this background, we conducted an experimental infection with H. pumilio to elucidate population dynamics and host reactions in dogs. Eight household-reared dogs (3-6 months old), were each orally infected with 500 H. pumilio metacercariae obtained by artificial digestion of naturally infected fish. Another eight dogs were included as uninfected controls. Faecal examination for eggs was performed twice weekly using a sieving and sedimentation technique. Body temperature and weight of the dogs were measured as was total white blood cells, blood eosinophils and packed cell volume. Subsets of dogs were examined post-mortem for presence of adult FZT at three different time points post infection by sectioning of the small intestine and caecum into four parts. Patent infections established in all eight infected dogs. The worm establishment ranged from 15 to 121 flukes (3-24%, mean 12%). Faecal egg excretion was measured in all eight infected dogs but no more than two eggs per g faeces (epg) were found at any time. Infections lasted for at least two months as documented by the presence of adult flukes in all three dogs necropsied on day 58 post infection. The predilection site of the flukes was identified as the lower part of jejunum (93% of total worm burden). The results of the haematological tests did not differ between the infected and uninfected group. Further, no clinical symptoms were observed in the infected group and no macroscopic pathological changes could be assigned to the trematode infections, neither did histopathological examination of the intestine reveal any differences between the infected and the control dogs. This study provides the first basic knowledge on the establishment, duration and location of H. pumilio infection in dogs. However, before any control measures can be recommended, knowledge regarding infection dynamics, epidemiology, health impact and control is needed.
Veterinary Parasitology, 2013, Vol 191, Issue 1-2, p. 138-142
The Faculty of Health and Medical Sciences; Dogs; Fish-borne zoonotic trematode; Minute intestinal flukes; Haplorchis pumilio; Vietnam