Introduction: Schistosomiasis, also known as bilharzia or snail fever, is a tropical parasitic disease caused by a trematode platyhelminthes called
Schistosoma
sp.
Schistosoma species are transmitted by cercariae penetrating the skin when a person is bathing, washing clothes, fishing or engaged in agricultural activities; involving contact with fresh water that has fecal or urinary contamination, and contains the parasites’ snail host. The present study aimed to survey freshwater snails in Kayonza District (Rwanda) especially Lake Muhazi and surrounding water bodies, stream and swamps to assess the potential for transmission of two species of Schistosoma:
S. mansoni
and
S. haematobium
.
Methods: Six sites were selected to assess the potential for transmission of schistosomiasis. The intermediate hosts of schistosomes, namely the snails
Biomphalaria
,
Bulinus
sp. and
Lymnaea
sp., were collected and brought to the laboratory and investigated to see if trematode cercaria responsible for the disease were present.
Results: Snails dissected were not only infected with trematode cercaria but also with annelids and flatworms (Platyhelminths). Cercaria found therein were of two types: furcocercous, probably responsible for schistosomiasis; and gymnocephalous cercaria for fasciolasis: an infection of cattle, goats and sheep.
Conclusion: Biomphalaria sp were the major hosts for schistosome cercaria, and most snails collected of this species were infected. Moreover, they were found in large number from all sites.
Lymnaea sp, hosts snails for
Fasciola cercaria
, were also found in a considerable number compared to the low number of
Bulinus sp in the region. District and national authorities may wish to further investigate this infestation and identify potential interventions to disrupt the disease transmission.
