Epidemiological and molecular evidence supports the zoonotic transmission of Giardia among humans and dogs living in the same community.
Giardia duodenalis isolates recovered from humans and dogs living in the same locality in a remote tea-growing community of northeast India were characterized at 3 different loci; the SSU-rDNA, elongation factor 1-alpha (ef1-alpha) and triose phosphate isomerase (tpi) gene. Phylogenetic analysis of the SSU-rDNA and efl-alpha genes provided poor genetic resolution of the isolates within various assemblages, stressing the importance of using multiple loci when inferring genotypes to Giardia. Analysis of the tpi gene provided better genetic resolution and placed canine Giardia isolates within the genetic groupings of human isolates (Assemblages A and B). Further evidence for zoonotic transmission was supported by epidemiological data showing a highly significant association between the prevalence of Giardia in humans and presence of a Giardia-positive dog in the same household (odds ratio 3.01, 95% CI, 1.11, 8.39, P = 0.0000).
Traub
R J
RJ
World Health Organization Collaborating Centre for the Molecular Epidemiology of Parasitic Infections, School of Veterinary and Biomedical Sciences, Murdoch University, South Street, Murdoch, Western Australia 6150.
Monis
P T
PT
Robertson
I
I
Irwin
P
P
Mencke
N
N
Thompson
R C A
RC
D000293:Adolescent; D000328:Adult; D000818:Animals; D001483:Base Sequence; D002648:Child; D002675:Child, Preschool; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D004283:Dog Diseases / Q000469:parasitology*; D004285:Dogs; D005260:Female; D005872:Giardia / Q000235:genetics / Q000254:growth & development*; D005873:Giardiasis / Q000453:epidemiology / Q000469:parasitology* / Q000635:transmission / Q000662:veterinary*; D006801:Humans; D007194:India / Q000453:epidemiology; D007223:Infant; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D020648:Peptide Elongation Factor 1 / Q000737:chemistry / Q000235:genetics; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012335:RNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014305:Triose-Phosphate Isomerase / Q000737:chemistry / Q000235:genetics; D015047:Zoonoses / Q000453:epidemiology / Q000469:parasitology* / Q000635:transmission
D016054:DNA, Protozoan; D020648:Peptide Elongation Factor 1; D012335:RNA, Ribosomal; D014305:Triose-Phosphate Isomerase