Molecular Prevalence and Subtypes Distribution of Blastocystis spp. in Humans of Latin America: A Systematic Review

Abstract

Blastocystis spp. are among the few enteric parasites with a prevalence that can reach up to approximately 80% in communities of developing countries. This systematic review updates and summarizes available literature on the molecular prevalence and subtype distribution of Blastocystis spp. in Latin American people. This work follows the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The literature revised covers from 1 January 2015 to 6 October 2023 in seven different scientific databases, and the material was selected through inclusion and exclusion criteria. According to data found in the 36 selected articles, the prevalence of Blastocystis spp. in Latin America ranged between 5.8% (Bolivian rural communities) and 94.0% (Colombian general public). Generally, genomic DNA was extracted from approximately 200 mg fecal sediments using commercial kits, such as the QIAamp Stool Mini Kit (QIAGEN, Hilden, Germany) or the Norgen Stool DNA Isolation Kit (Norgen Biotek Corporation, Thorold, ON, Canada). Subtype-specific primers (such as the couple of primers BhRDr–RD5) developed from unique sequences of the SSU rRNA gene were applied to Blastocystis subtyping. Ten specific subtypes (STs) were found as well as various mixed infections, and the most circulating Blastocystis STs were in the order ST3, ST1, ST2, and ST4. The most recent data about Blastocystis spp. molecular epidemiology and the STs in communities of Latin America are limited to studies from specific countries. Novel scientific data from the other countries are required to obtain a complete picture and truly understand the distribution and prevalence of Blastocystis spp. and the STs.

Prevalence of Intestinal Parasites, Protozoans and Soil-Transmitted Helminths, in Children from Communities of Northern Argentina after the Interruption of Deworming

“…The genus Blastocystis comprises a variety of lineages, called STs, and more than 90% of human isolates are grouped into STs 1-4 [39]. The distribution of STs in our samples demonstrated that ST3 was the most frequently detected ST, followed by ST2 and ST1, as other studies have reported [20,40,41]. Several authors have reported gastrointestinal symptoms associated with ST3 [42][43][44], and more specifically, the possible pathogenic association of allele 34, the most common in our study (57.9%; 11/19) with urticaria [39,42].…”