[A Retrospective Study on Planorbarius metidjensis and Its Role as a Potential Intermediate Host in the Transmission of Schistosoma haematobium in the Souss-Massa Region (Morocco)].

A retrospective research study was carried out by our team on Planorbarius metidjensis to highlight its epidemiological role as a potential host snail of Schistosoma haematobium in the Souss-Massa region. Contrary to the habitats colonized by Bulinus truncatus, the main host snail, those of P. metidjensis are located at the altitude of above 300 m. The best results of the experimental infections with S. haematobium were obtained using juvenile planorbids of 2 to 3 mm in diameter and a dose of five miracidia per snail. No snail naturally infected with the parasite was found when dissecting 3,457 adult bulinids and 2,470 adult planorbids. Despite the location of its habitats in altitude, P. metidjensis is a potential intermediate host of S. haematobium and it is important to follow these populations, as those of B. truncatus, in the future to avoid possible reoccurrence of indigenous cases of the disease.