Distribution of Giardia duodenalis Assemblages by PCR-RFLP of β-Giardin Gene in Cuban Children

Giardia duodenalis is one of the most prevalent intestinal parasites worldwide that infect humans, especially children. This study was aimed to determine the prevalence of assemblages of Giardia among a group of children. A descriptive cross-sectional study was performed in the Pediatric Academic Hospital “William Soler” from January 2014 to September 2014 in 286 children as part of a surveillance program of intestinal parasitic infections in scholar children. Out of 286 samples examined, 27 were positive for G. duodenalis for an infection rate of 9.34%. All Giardia positive samples were successfully amplified by a polymerase chain reaction (PCR) assay targeting the β-giardin gene. Restriction fragment length polymorphism analysis of these PCR products revealed that children infected with assemblage B were more prevalent (19/27; 70.4%) than those who harbored assemblage A (8/27; 29.6%) of this parasite. Abdominal pain was statistically associated with the infecting assemblage B of Giardia. The sequence of PCR products of β-giardin gene from symptomatic children infected with assemblage A revealed a distribution of four subassemblages AII divided in two subtypes A3 and two A2. Cases infected with subassemblage AII-A3 had a more abrupt onset of symptomatology. These findings highlighted the use of novel molecular tools for a better discrimination of assemblages at the subassemblages and genotypes levels are needed to verify possible correlations between Giardia genotypes and symptomatology of giardiasis.