Little information is available on the occurrence and genetic variability of the diarrhoea-causing enteric protozoan parasite Giardia duodenalis in indigenous communities in Brazil. This cross-sectional epidemiological survey describes the frequency, genotypes, and risk associations for this pathogen in Tapirape people (Brazilian Amazon) at four sampling campaigns during 2008-2009. Microscopy was used as a screening test, and molecular (PCR and Sanger sequencing) assays targeting the small subunit ribosomal RNA, the glutamate dehydrogenase, the beta-giardin, and the triosephosphate isomerase genes as confirmatory/genotyping methods. Associations between G. duodenalis and sociodemographic and clinical variables were investigated using Chi-squared test and univariable/multivariable logistic regression models. Overall, 574 individuals belonging to six tribes participated in the study, with G. duodenalis prevalence rates varying from 13.5-21.7%. The infection was positively linked to younger age and tribe. Infected children G. duodenalis infections and showed a high genetic diversity. No association between assemblage and age or occurrence of diarrhoea was demonstrated. These data indicate that the most likely source of infection was anthropic and that different pathways (e.g., drinking water) may be involved in the transmission of the parasite.
Bibliographical noteFunding Information:
Funding: This research was funded by the São Paulo State Research Support Foundation (FAFESP, Brazil), the National Health Foundation (FUNASA, Brazil), and the Mato Grosso State Research Support Foundation (FAPEMAT, Brazil), grant number 0839/2006. Additional funding was obtained from the Health Institute Carlos III (ISCIII), Ministry of Economy and Competitiveness (Spain), grant number PI16CIII/00024.
Acknowledgments: S.M. Gennari, A. Marcili, and J. J. Shaw are in receipt of a Research Productivity Fellowship from the National Council for Scientific and Technological Development (CNPq, Brazil).
This research was funded by the S?o Paulo State Research Support Foundation (FAFESP, Brazil), the National Health Foundation (FUNASA, Brazil), and the Mato Grosso State Research Support Foundation (FAPEMAT, Brazil), grant number 0839/2006. Additional funding was obtained from the Health Institute Carlos III (ISCIII), Ministry of Economy and Competitiveness (Spain), grant number PI16CIII/00024.
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- Risk association
- MOLECULAR CHARACTERIZATION
- ZOONOTIC TRANSMISSION
- DIARRHEAL DISEASE
- SAO-PAULO STATE
- risk association