title: Blastocystis sp.: waterborne zoonotic organism, a possibility?
abstract: BACKGROUND
  Blastocystis sp. is a common intestinal parasite found in faecal sample surveys. Several studies have implicated human-to-human, zoonotic and waterborne transmissions by Blastocystis sp. However, there has been no study providing evidence interlinking these three transmissions in a community. We have previously shown a high prevalence of Blastocystis sp. subtype 4 amongst village dwellers in Bahunipati, Nepal, and the present study extends the observation to assess if the same subtype of Blastocystis sp. occurs in animals they rear and rivers they frequent.
  
  
  METHODS
  Faecal samples were collected from 65 animals. Four river water samples were collected from two rivers. Faecal samples were examined using in vitro cultivation. Blastocystis sp. from animal faecal and river samples were genotyped using seven subtype-specific sequence tagged site (STS) primer-polymerase chain reaction (PCR).
  
  
  RESULTS
  Blastocystis sp. infected 15.4% animals with subtype 4 being the predominant genotype (40.0%). Both rivers were contaminated with Blastocystis sp. subtype 1 and subtype 4, which were also detected in humans living in the same village in our previous study. Blastocystis sp. subtype 4 that was detected in buffalo and pigs was also found in the respective family members that reared these animals.
  
  
  CONCLUSIONS
  This unusually high prevalence of Blastocystis subtype 4 found in village dwellers was also found to be pervasive in the animals they reared and the rivers they frequented implying a strong possibility of waterborne zoonosis for Blastocystis sp.
authors: Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603, Malaysia.
authors: Li Ii
authors: LI
authors: Lee
authors: Tan Tian
authors: TT
authors: Chye
authors: Biraj Man
authors: BM
authors: Karmacharya
authors: Suresh Kumar
authors: SK
authors: Govind
mesh_terms: D000818:Animals; D016844:Blastocystis / Q000145:classification* / Q000302:isolation & purification*; D003430:Cross-Sectional Studies; D005243:Feces / Q000469:parasitology; D006801:Humans; D009390:Nepal; D045483:Rivers / Q000469:parasitology*; D012418:Ruminants; D012424:Rural Population; D013552:Swine; D014867:Water / Q000469:parasitology*
chemical_list: D014867:Water