title: Reinfection of dogs with fish-borne zoonotic trematodes in northern Vietnam following a single treatment with praziquantel.
abstract: BACKGROUND
  Fish-borne zoonotic trematodes (FZT) infections including liver- and minute intestinal flukes are common in Southeast Asia in both humans and domestic animals eating raw fish and since 2010, the liver flukes are recognised as neglected tropical diseases by WHO. Mass drug treatment with praziquantel is advised for humans, but no recommendations for control of the FZT in the reservoir hosts exist.
  
  
  RESULTS
  A study was conducted to assess the ability of praziquantel treatment for control of FZT in farm dogs in an endemic area in Northern Vietnam. Initially, 101 dogs from 73 households were examined for small trematode eggs in their faeces. Forty seven copro-positive dogs were included in the study. Thirty eight dogs received treatment with a single dose of 40 mg/kg of praziquantel. A group of nine dogs were left untreated. Coprological examination for small trematode eggs was performed on day 0, 3, 10, 30, 60, 90 and 120 post treatment. Farmers were questioned about dog keeping practises. All dogs were copro-negative for small trematode eggs on both day 3 and 10 post treatment. From day 30 onwards previously negative dogs became positive again. The reinfection rates were 26.3% (day 30), 45.5% (day 60), 53.1% (day 90), 61.3% (day 120).The nine untreated dogs remained positive throughout the study period. There was no difference in the intensity of infection at day 0 and 120 neither in the treated or untreated group.
  
  
  CONCLUSIONS
  Dogs had easy access to raw fish and did not receive treatment against flukes by their owner. More than 50% of the dogs were reinfected 3 months post treatment. We do not recommend controlling FZT infections in dogs by anthelmintic treatment alone since reinfection occurs fast under the existing farm management systems.
authors.affiliation: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark.
authors.forename: Sofie
authors.initials: S
authors.lastname: Nissen
authors.affiliation: National Institute for Veterinary Research, Hanoi, Vietnam.
authors.forename: Lan Anh Thi
authors.initials: LA
authors.lastname: Nguyen
authors.affiliation: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark.
authors.forename: Stig Milan
authors.initials: SM
authors.lastname: Thamsborg
authors.affiliation: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark.
authors.forename: Anders
authors.initials: A
authors.lastname: Dalsgaard
authors.affiliation: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark.
authors.forename: Maria Vang
authors.initials: MV
authors.lastname: Johansen
mesh_terms: D000818:Animals; D000977:Antiparasitic Agents / Q000627:therapeutic use*; D004283:Dog Diseases / Q000188:drug therapy* / Q000469:parasitology; D004285:Dogs; D005243:Feces / Q000469:parasitology*; D005260:Female; D005517:Foodborne Diseases / Q000188:drug therapy / Q000469:parasitology / Q000662:veterinary*; D008297:Male; D011223:Praziquantel / Q000627:therapeutic use*; D012008:Recurrence; D014200:Trematoda / Q000302:isolation & purification*; D014201:Trematode Infections / Q000188:drug therapy / Q000469:parasitology / Q000662:veterinary*; D014744:Vietnam
chemical_list: D000977:Antiparasitic Agents; D011223:Praziquantel