title: Molecular epidemiology of giardiasis among Orang Asli in Malaysia: application of the triosephosphate isomerase gene.
abstract: BACKGROUND
  Giardia duodenalis is a flagellate parasite which has been considered the most common protozoa infecting human worldwide. Molecular characterization of G. duodenalis isolates have revealed the existence of eight groups (Assemblage A to H) which differ in their host distribution. Assemblages A and B are found in humans and in many other mammals.
  
  
  METHODS
  This cross-sectional study was conducted to identify assemblage's related risk factors of G. duodenalis among Orang Asli in Malaysia. Stool samples were collected from 611 individuals aged between 2 and 74 years old of whom 266 were males and 345 were females. Socioeconomic data were collected through a pre-tested questionnaire. All stool samples were processed with formalin-ether sedimentation and Wheatley's trichrome staining techniques for the primary identification of G. duodenalis. Molecular identification was carried out by the amplification of a triosephosphate isomerase gene using nested-PCR assay.
  
  
  RESULTS
  Sixty-two samples (10.2%) were identified as assemblage A and 36 (5.9%) were assemblage B. Risk analysis based on the detected assemblages using univariate and logistic regression analyses identified subjects who have close contact with household pets i.e. dogs and cats (OR = 2.60; 95% CI = 1.42, 4.78; P = 0.002) was found to be significant predictor for assemblage A. On the other hand, there were three significant risk factors caused by assemblage B: (i) children ≤15 years old (OR = 2.33; 95% CI = 1.11, 4.87; P = 0.025), (ii) consuming raw vegetables (OR = 2.82; 95% CI = 1.27, 6.26; P = 0.011) and (iii) the presence of other family members infected with giardiasis (OR = 6.31; 95% CI = 2.99, 13.31; P < 0.001).
  
  
  CONCLUSIONS
  The present study highlighted that G. duodenalis infection among Orang Asli was caused by both assemblages with significant high prevalence of assemblage A. Therefore, taking precaution after having contact with household pets and their stool, screening and treating infected individuals, awareness on the importance of good health practices and washing vegetables are the practical intervention ways in preventing giardiasis in Orang Asli community.
authors: Tengku Shahrul
authors: TS
authors: Anuar
authors: Siti Nor
authors: SN
authors: Azreen
authors: Fatmah Md
authors: FM
authors: Salleh
authors: Department of Parasitology and Medical Entomology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia. tsatab@lycos.com.
authors: Norhayati
authors: N
authors: Moktar
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D002415:Cats; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004285:Dogs; D005243:Feces / Q000469:parasitology; D005260:Female; D016829:Giardia lamblia; D005873:Giardiasis / Q000453:epidemiology*; D006801:Humans; D008296:Malaysia / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D057805:Pets; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D015995:Prevalence; D012307:Risk Factors; D012923:Social Class; D011795:Surveys and Questionnaires; D014305:Triose-Phosphate Isomerase / Q000235:genetics*; D055815:Young Adult
chemical_list: D014305:Triose-Phosphate Isomerase