Background: Intestinal schistosomiasis due to Schistosoma mansoni was mapped in Cameroon in the 1990s and
preventive chemotherapy launched since 2005. A situation analysis conducted in 2011 revealed an increase in
schistosomiasis transmission, especially in the equatorial part of the country, despite the fact that Biomphalaria
pfeifferi, the main intermediate host of this parasite, is now scarce in many foci. Biomphalaria camerunensis,
restricted to the equatorial part of the country, is considered as a less suitable host for S. mansoni due to it
resistance to the parasite, although exhibiting a better survival than B. pfeifferi. In a context where human migration
is quite frequent as a consequence of terrorism, war in neighboring countries, as well as development of hydraulic
projects, it seems appropriate to evaluate the current epidemiological role of B. camerunensis to estimate the risk of
extension of S. mansoni distribution in Cameroon. To do this, the susceptibility of three B. pfeifferi and five B.
camerunensis populations to a strain of S. mansoni was assessed. Juvenile snails (G1) of each population were
infected with S. mansoni miracidia, and prepatent period, infection and survival rates of infected snails, as well as
cercarial production were recorded and compared between snail species and populations.
Results: Compatibility tests were performed on a total of 827 snails: 344 B. pfeifferi and 483 B. camerunensis. Infection rates were quite heterogeneous, higher in B. pfeifferi (61.5%) as compared to B. camerunensis (7.8%) (Chi-square test: χ2= 258.88, df = 1, P

Biomphalaria pfeifferi Biomphalaria camerunensis Schistosoma mansoni Compatibility Cercarial production Cameroon