Parasitology Research

, Volume 111, Issue 3, pp 1045–1048 | Cite as

Evaluation of the role of rats as reservoir hosts for fishborne zoonotic trematodes in two endemic northern Vietnam fish farms

  • Nguyen Lan Anh Thi
  • Henry Madsen
  • Dao Thanh Ha
  • Eric Hoberg
  • Anders Dalsgaard
  • K. Darwin MurrellEmail author
Original Paper


Fishborne zoonotic trematodes (FZTs) pose a food safety risk for the aquaculture industry in Vietnam. The risk of being infected from eating raw fish applies not only to humans but also to domestic animals which can serve as reservoir hosts in fish farms. The role of rodents, commonly found in fish farms, as reservoir hosts has not been adequately evaluated. To study this question, commensal and rice field rats were collected from fish farms in Nghia Lac and Nghia Phu communes, Nam Dinh province, Vietnam and examined for FZT infection. A total of 250 rats (Rattus norvegicus, Rattus argentiventer, and Bandicota indica) were collected and examined; the rats were trapped in the farm households (commensal) and in rice fields adjoining the fish ponds (field). The total prevalence of all parasites was 52.8 %: nematodes, 42.4 %; trematodes 18.0 %; and cestodes, (3.6 %), including two zoonotic cestode species, Raillietina celebenisis and Hymenolepis diminuta. Although overall prevalence and intensity of parasite infection did not differ significantly among rat species or between the two communes, the intensity of nematode infection was significantly higher in commensal rats (p < 0.05). The only FZTs recovered were the intestinal flukes Echinostoma cinetorchis and Centrocestus formosanus, both at low prevalence. Because the most common FZTs found in fish from these communes are Haplorchis pumilio and Haplorchis taichui, neither of which were found in the rats, we conclude that rats are not significant reservoir hosts for FZT in these Vietnamese fish farms.


Rice Field Farm Household Fish Pond Reservoir Host Farm Pond 
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The authors appreciate the cooperation extended by the farmers who participated in this study. We are grateful to Dr. Nguyen Truong Son, Institute of Ecology and Biological Resources, Vietnamese Academy of Science and Technology, Hanoi for help on identification of the rats. Appreciation is also expressed to Dr. Van Thi Phan, Director of the Fibozopa Project in Vietnam for her strong support of the study. The Danish International Development Assistance (Danida) is gratefully acknowledged for its financial support to this study through the project titled “Fish Borne Zoonotic Parasite in Vietnam” ( We thank Patricia Pilitt of the US National Parasite Collection for assisting in access to comparative specimens used in confirmation of identification for some parasites.


  1. Anh NTL, Madsen H, Dalsgaard A, Phoung NT, Thanh DTH, Murrell KD (2010) Poultry as reservoir hosts for fishborne zoonotic trematodes in Vietnam fish farms. Vet Parasitol 169:391–394PubMedCrossRefGoogle Scholar
  2. Anh NTL, Phuong T, Murrell KD, Johansen MV, Dalsgaard A, Thu KT, Chi TT, Thamsborg SM (2009) Animal reservoir hosts and fish-borne zoonotic trematodes in fish farms, Vietnam, 2009. Emerg Infect Dis 15:540–546CrossRefGoogle Scholar
  3. Chai JY, Hong ST, Lee SH, Lee GC, Min YI (1994) A case of echinostomiasis with ulcerative lesions in the duodenum. Korean J Parasitol 32:201–204PubMedCrossRefGoogle Scholar
  4. Chang YD, Sohn WM, Ryu JH, Kang SY, Hong SJ (2005) A human infection of Echinostoma hortense in duodenal bulb diagnosed by endoscopy. Korean J Parasitol 43:57–60PubMedCrossRefGoogle Scholar
  5. Chi Tran TK, Dalsgaard A, Turnbull JF, Tuan PA, Murrell KD (2008) Prevalence of zoonotic trematodes in fish from a Vietnamese fish-farming community. J Parasitol 94:423–428PubMedCrossRefGoogle Scholar
  6. Cho CM, Tak WY, Yo K, Kim SK, Choi YH, Kong HH, Chung DI (2003) A human case of Echinostoma hortense (Trematode: Echinostomatidae) infection diagnosed by gastroduodenal endoscopy in Korea. Korean J Parasitol 41:117–120PubMedCrossRefGoogle Scholar
  7. Corbet GB, Hill JE (1991) A world list of mammalian species, 3rd edn. British Museum (Natural History) Publications, LondonGoogle Scholar
  8. Corbet GB, Hill JE (1992) Mammals of the Indomalayan Region. A systematic review. Oxford University Press, OxfordGoogle Scholar
  9. Dung DT, De NV, Waikagul J, Dalsgaard A, Chai JY, Sohn WM, Murrell KD (2007) Fishborne intestinal zoonotic trematodes, Vietnam. Emerg Infect Dis 12:1828–1833CrossRefGoogle Scholar
  10. Fried B, Toledo R (2009) The biology of echinostomes. In: Chai JY (ed) Echinostomes in humans, 1st edn. Springer, New York, pp 47–183Google Scholar
  11. Hilbe JM (2009) Logistic regression models. Chapman & Hall, Boca RatonGoogle Scholar
  12. Kataranovski M, Mirkov I, Belij S, Popov A, Gaci Z (2011) Intestinal helminths infection of rats (Rattus norvegicus) in the Belgrade area (Serbia): the effect of sex, age and habitat. Parasite 18:189–196PubMedGoogle Scholar
  13. Kiitipong C, Vincent H, Alexis R, Serge M (2010) A study of great Bandicoot (Bandicota indica) and their gastrointestinal helminths from Northern and Northeastern Thailand. J Trop Med Parasitol 33:29–35Google Scholar
  14. Lee SK, Chung NS, Ko IH, Ko HI (1988) A case of natural infection by Echinostoma cinetorchis. Korean J Parasitol 26:61–64CrossRefGoogle Scholar
  15. Miyazaki I (1991) Helminthic zoonoses. International Medical Foundation of Japan, SEAMIC Publication No. 62, TokyoGoogle Scholar
  16. Pearson JC, Ow-Yang CK (1982) New species of Haplorchis from Southeast Asia, together with keys to the Haplorchis-group of heterophyid trematodes of the region. Southeast Asian J Trop Med Publ Hlth 13:35–60Google Scholar
  17. Pham XD, Tran CL (2001) Helminths collected from Rattus spp. in Bac Ninh province, Vietnam. Comp Parasitol 68:261–264Google Scholar
  18. Phan VT, Ersbøll AK, Te BQ, Hang TN, Murrell KD, Dalsgaard A (2010) Fish-borne zoonotic trematodes in cultured and wild-caught freshwater fish from the Red River Delta, Vietnam. Vector Borne Zoonotic Dis 10:861–862PubMedCrossRefGoogle Scholar
  19. Rougier Y, Legros F, Durand JP, Corliani Y (1981) Four cases of parasitic infection by Raillietina celebensis in French Polynesia. Trans R Soc Trop Med Hyg 75:121–126PubMedCrossRefGoogle Scholar
  20. Scholtz T (2008) Family Opisthirchiidae Loos, 1899. Chapter 2. In: Bray RA, Gibson DI, Jones A (eds) Keys to the Trematoda, vol 3. CABI, Oxfordshire, pp 9–50Google Scholar
  21. Seo BS, Cho SY, Hong ST, Hong SJ, Lee SH (1981) Studies on parasitic helminthes of Korea. V. Survey on intestinal trematodes of house rats. Korean J Parasitol 19:131–136CrossRefGoogle Scholar
  22. Thien PC, Dalsgaard A, Thanh BG, Olsen AE, Murrell KD (2007) Prevalence of fishborne zoonotic parasites in important cultured fish species in the Mekong Delta, Vietnam. Parasitol Res 101:1277–1284PubMedCrossRefGoogle Scholar
  23. Yamaguti S (1971) Synopsis of digenetic trematodes of vertebrates, vol 1 and 2. Keigeku Publishing Company, TokyoGoogle Scholar
  24. Yorke W, Maplestone PA (1969) The nematode parasites of vertebrates. Hafner Publishing Company, New YorkGoogle Scholar

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Nguyen Lan Anh Thi
    • 1
  • Henry Madsen
    • 2
  • Dao Thanh Ha
    • 1
  • Eric Hoberg
    • 3
  • Anders Dalsgaard
    • 2
  • K. Darwin Murrell
    • 2
    Email author
  1. 1.National Institute for Veterinary ResearchHanoiVietnam
  2. 2.Department of Veterinary Disease Biology, Faculty of Health and Medical SciencesUniversity of CopenhagenFrederiksberg CDenmark
  3. 3.US National Parasite Collection, Animal Parasitic Diseases LaboratoryBeltsville Agricultural Research Center, Agricultural Research ServiceBeltsvilleUSA

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