Schistosomiasis remains a great public health problem in several tropical and subtropical countries. Recently in Côte
d’Ivoire, we have investigated hybrids between S. haematobium and S. bovis in human urine samples. Moreover, S.
haematobium x S. mansoni hybrid has recently been identified in a French hospital in a migrant boy originated from
Duekoué, western part of the country. The aim of this project was to molecularly characterize Schistosoma mansoni
among schoolchildren in Côte d’Ivoire. A cross-sectional study was conducted in two localities of Côte d'Ivoire
(Agboville and Duekoué). Stool samples were collected from schoolchildren and examined by Kato-Katz method to
identify Schistosoma eggs. Miracidia were individually isolated and stored on Whatman ® FTA card. We analyzed
miracidia from stool samples using a Cox1 gene multiplex PCR. Nuclear ITS gene has not been analyzed. A total of
661 schoolchildren was included in this study. More boys than girls (61.9% vs. 38.1%) were included and the highest
proportion of children was included in Agboville. The overall prevalence of S. mansoni infection was 9.8% (95% CI:
4.8-13.5%). Of the 239 miracidia molecularly analyzed, 166 yielded positive PCR signal (82.5% in Agboville and 17.5%
in Duekoué). Only one case of S. haematobium Cox1 has been identified in Agboville. This case should be hybrid S.
haematobium x S. mansoni. Our study reports that intestinal schistosomiasis remains prevalent even if the infection
rate was low. Only one case of S. haematobium Cox1 was identified, suggesting the presence of S. haematobium x S.
mansoni hybrids at very low prevalence.
While population genetics of Schistosoma haematobium have been investigated in West Africa, only scant
data are available from Côte d ’ Ivoire. The purpose of this study was to analyze both genetic variability and genetic
structure among S. haematobium populations and to quantify the frequency of S. haematobium S. bovis hybrids
in school-aged children in different parts of Côte d ’ Ivoire. Urine samples were subjected to a fi ltration method and
examined microscopically for Schistosoma eggs in four sites in the western and southern parts of Côte d ’ Ivoire. A total
of 2692 miracidia were collected individually and stored on Whatman
FTA cards. Of these, 2561 miracidia were suc-
cessfully genotyped for species and hybrid identi fi cation using rapid diagnostic multiplex mitochondrial cox1 PCR and
PCR Restriction Fragment Length Polymorphism (PCR-RFLP) analysis of the nuclear ITS2 region. From 2164 mira-
cidia, 1966 (90.9%) were successfully genotyped using at least 10 nuclear microsatellite loci to investigate genetic
diversity and population structure. Signi fi cant differences were found between sites in all genetic diversity indices
and genotypic differentiation was observed between the site in the West and the three sites in the East. Analysis at
the infrapopulation level revealed clustering of parasite genotypes within individual children, particularly in Duekoue
(West) and Sikensi (East). Of the six possible cox1-ITS2 genetic pro fi les obtained from miracidia, S. bovis
cox1 S. haematobium ITS2 (42.0%) was the most commonly observed in the populations. We identi fi ed only
15 miracidia (0.7%) with an S. bovis cox1 S. bovis ITS2 genotype. Our study provides new insights into the
population genetics of S. haematobium and S. haematobium S. bovis hybrids in humans in Côte d ’ Ivoire and we
advocate for researching hybrid schistosomes in animals such as rodents and cattle in Côte d ’ Ivoire.