Bulinus senegalensis and Bulinus umbilicatus Snail Infestations by the Schistosoma haematobium Group in Niakhar, Senegal

Papa Mouhamadou Gaye , Souleymane Doucoure (1) , Bruno Senghor (2) , Babacar Faye (3) , Ndiaw Goumballa (2) , Mbacké Sembène (4) , Coralie L’ollivier (2) , Philippe Parola (2) , Stéphane Ranque (2) , Doudou Sow (2) , Cheikh Sokhna (1)

1 Equipe 3 - VITROME - Maladies infectieuses persistantes et émergentes en Afrique de l’Ouest [Dakar, Sénégal]
2 VITROME - Vecteurs - Infections tropicales et méditerranéennes
3 UCAD - Université Cheikh Anta Diop de Dakar [Sénégal]
4 Faculté des Sciences et Techniques (FST)

Thorough knowledge of the dynamics of Bulinus spp. infestation could help to control the spread of schistosomiasis. This study describes the spatio-temporal dynamics of B. senegalensis and B. umbilicatus infestation by the Schistosoma haematobium group of blood flukes in Niakhar, Senegal. Molecular identification of the S. haematobium group was performed by real-time PCR, targeting the Dra 1 gene in 810 samples of Bulinus spp. collected during the schistosomiasis transmission season in 2013. In addition to Dra 1 PCR, a rapid diagnostic-PCR was performed on a sub-group of 43 snails to discriminate S. haematobium, S. bovis, and S. mattheei. Out of 810 snails, 236 (29.1%) were positive for Dra 1 based on the PCR, including 96.2% and 3.8% of B. senegalensis and B. umbilicatus, respectively. Among the sub-group, 16 samples were confirmed to be S. haematobium while one was identified as a mixture of S. haematobium and S. bovis. Snails infestations were detected in all villages sampled and infestation rates ranged from 15.38% to 42.11%. The prevalence of infestation was higher in the north (33.47%) compared to the south (25.74%). Snail populations infestations appear early in the rainy season, with a peak in the middle of the season, and then a decline towards the end of the rainy season. Molecular techniques showed, for the first time, the presence of S. bovis in the Bulinus spp. population of Niakhar. The heterogeneity of snail infestations at the village level must be taken into account in mass treatment strategies. Further studies should help to improve the characterizations of the schistosome population.

Mots clés: schistosomiasis; Schistosoma haematobium-group; S. bovis; Bulinus senegalensis; Bulinus umbilicatus; Dra1; RD-PCR; Niakhar

Domaines: Bactériologie; Cardiologie et système cardiovasculaire; Maladies émergentes; Maladies infectieuses; Parasitologie; Virologie

Papa Mouhamadou Gaye, Souleymane Doucoure, Bruno Senghor, Babacar Faye, Ndiaw Goumballa, et al.. Bulinus senegalensis and Bulinus umbilicatus Snail Infestations by the Schistosoma haematobium Group in Niakhar, Senegal. Pathogens, 2021, 10 (7), pp.860. ⟨10.3390/pathogens10070860⟩. ⟨hal-03421051⟩