Molecular Characterization and Risk Factors ofGiardia duodenalisamong School Children from La Habana, Cuba

Abstract

Giardia duodenalis is considered the most common protozoan infecting humans worldwide. Molecular characterization of G. duodenalis isolates has revealed the existence of eight groups (assemblages A to H) which differ in their host distribution. A cross-sectional study was conducted in 639 children from La Habana between January and December 2013. Two assemblage-specific PCRs were carried out for the molecular characterization. The overall prevalence of Giardia infection was 11.9%. DNA from 63 of 76 (82.9%) samples was successfully amplified by PCR-tpi, while 58 from 76 (76.3%) were detected by PCRE1-HF. Similar results by both PCRs were obtained in 54 from 76 samples (71%). According to these analyses, assemblage B and mixed assemblages A + B account for most of the Giardia infections in the cohort of children tested. Our current study identified assemblage B as predominant genotype in children infected with Giardia. Univariate analysis indicated that omission of washing hands before eating and keeping dogs at home were significant risk factors for a Giardia infection. In the future, novel molecular tools for a better discrimination of assemblages at the subassemblages level are needed to verify possible correlations between Giardia genotypes and symptomatology of giardiasis.

Molecular diversity of Giardia duodenalis in children under 5 years from the Manhiça district, Southern Mozambique enrolled in a matched case-control study on the aetiology of diarrhoea

“…As assemblage typing is a fundamental tool when studying the molecular epidemiology of G . duodenalis , simpler methods (such as assemblage-specific PCR protocols) have been developed and implemented in field surveys [ 21 , 22 , 28 , 29 ].…”

“…However, this typing strategy has some disadvantages such as the intrinsic complexity of molecular methods (nested-PCR followed by either restriction length fragment polymorphisms or DNA sequencing) and the requirement for equipment which is not readily available for most laboratories due to elevated costs among other factors. As assemblage typing is a fundamental tool when studying the molecular epidemiology of G. duodenalis, simpler methods (such as assemblage-specific PCR protocols) have been developed and implemented in field surveys [21,22,28,29].…”

Evaluation of Three Protocols of DNA Extraction for Detection of Giardia duodenalis in Human Fecal Specimens

“…In addition, the ease-of-use, simplicity, and cost-effectiveness are among the essential selection criteria. However in some molecular assays, false-negative results have been reported despite the microscopic detection of G. duodenalis in wet mount smears of fecal specimens (4,7,28). The failure of target gene amplification may be due to inefficient breakdown of cyst wall, which consequently lead to decrease in quantity of the released DNA, in addition to disruption, and contamination of extracted DNA with impurities such as PCR inhibitors (5).…”

“…Direct life cycle of G. duodenalis composed of 2 main stages: the infective cyst, resistant to environmental conditions, and the vegetative trophozoites, which live in the lumen of the small intestine and can cause a problem in infected individuals (4)(5)(6). Annually, about 200 million people are affected with symptomatic giardiasis in Asia, Africa, and Latin America (6,7). Giardia infections cause an economic burden in public health and veterinary (3,(8)(9)(10).…”

Occurrence of Giardia duodenalis in Cats from Queretaro and the Risk to Public Health

“…The most common signs of giardiosis include diarrhea, steatorrhea, abdominal pain, and weight loss [ 11 ]. Clinical manifestation of giardiosis may also be related to the assemblages present, with assemblage A being associated with acute disease and the presence of explosive diarrhea, and assemblage B being associated with chronic disease [ 4 , 13 , 14 ].…”