Blastocystis in Côte d’Ivoire: molecular identification and epidemiological data

Abstract

Blastocystis is an enteric protozoan infecting humans and animals in both developed and developing countries at all latitudes. Despite this, data on Blastocystis infection are not available for several geographical areas, including many African countries. In this study, a survey was conducted on Blastocystis among humans and domestic animals in rural and urban localities in Côte d'Ivoire, in order to investigate the prevalence, the subtype distribution, and the zoonotic potential in association with sociodemographic factors, seasonality, symptoms, and co-infections. A total of 110 fecal samples were collected from patients living in four localities. Molecular and phylogenetic analyses were conducted for Blastocystis detection and subtyping. Positive samples from symptomatic patients were tested by Luminex xTAG® Gastrointestinal Pathogen Panel (GPP) to evidence the presence of other common intestinal pathogens. Overall, a prevalence of 58.2% was observed in humans and subtypes ST1(50.0%), ST2 (22.0%) and ST3 (28.1%) were identified. The prevalence values varied significantly among the sites but not in relation to the subtype. The seasonal rains significantly increase the infection rate in all localities. No significant differences in the ST distribution between asymptomatic and symptomatic subjects were observed. As regard the zoonotic transmission, an additional sampling was conducted in another village where fecal samples were simultaneously collected from humans and animals. Blastocystis STs 1-3 and ST7 were identified in eight humans and four chickens, respectively. This study provides the first exhaustive data on the prevalence and molecular epidemiology of Blastocystis in Côte d'Ivoire.

Prevalence and Subtype Distribution of Blastocystis sp. in Senegalese School Children

“…In this aim, only data obtained by molecular methods were recorded as non-molecular methods such as microscopic observation of fresh feces are known to greatly underestimate the prevalence of the parasite [ 39 , 41 ]. The prevalence of the parasite ranges between 25.6% and 100% depending on the geographical area [ 12 , 13 , 31 , 36 , 37 , 38 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 ]. By focusing on the neighboring countries of Senegal (West Africa), the prevalence of Blastocystis sp.…”

“…By focusing on the neighboring countries of Senegal (West Africa), the prevalence of Blastocystis sp. was, respectively, 58.2% [ 38 ] and 70% [ 45 ] in two different surveys performed in Côte d’Ivoire and 49.7% in Mali [ 46 ]. Two other field studies showed a prevalence of 49% [ 31 ] and 84% [ 37 ] in Nigeria, while only one small-scale cohort screened in Liberia [ 31 ] indicated a frequency of the parasite of ~70%.…”

“…This ST distribution could first be compared with that observed in a previous survey conducted in children of the Podor district in Senegal, reporting the predominance of ST3 followed by ST1 and ST2 [ 12 ]. In other West African countries like Nigeria [ 31 , 37 ] and Côte d’Ivoire [ 38 ], ST1 was the predominant variant followed by either ST2 or ST3. Variation in ST distribution was also observed between other African regions as ST3 was predominant in Central [ 13 , 42 ] and North [ 36 , 47 , 49 , 50 , 51 ] Africa, with the exception of Libya, where ST1 was the most frequent ST [ 31 , 48 ] as in Southern Africa [ 44 ].…”

“…infection due to poor access to sanitation and clean water, thus favoring parasite transmission. To date, the available data mainly concerns few countries of the Northern, Western, and Central Africa such as Libya [ 31 ], Egypt [ 36 ], Nigeria [ 37 ], Côte d’Ivoire [ 38 ], Senegal [ 12 ], and Cameroon [ 13 ]. Moreover, these epidemiological studies remained based on cohorts still too limited in size.…”

Use of shotgun metagenomics for the identification of protozoa in the gut microbiota of healthy individuals from worldwide populations with various industrialization levels

“…remain scarce. Similarly, molecular methods unveiled high genetic diversity of Blastocystis sp., the most common single-celled eukaryote in fecal samples of healthy humans [12–19]: so far, 10 genetic subtypes (ST1–9 and ST12) have been found in humans, with ST3 being the most common [16]. Apart from Entamoeba and Blastocystis , other presumably non-pathogenic intestinal protozoa have been studied only exceptionally by molecular methods [1].…”