Compatibility of Ugandan Schistosoma mansoni isolates with Biomphalaria snail species from Lake Albert and Lake Victoria

In order to investigate the capacity of being intermediate host for Schistosoma mansoni, the Ugandan F1 generation of Biomphalaria snail species that were laboratory-bred from parent populations originally collected from either Lake Victoria or Lake Albert was challenged with sympatric and non-sympatric S. mansoni isolates. After a prepatent period of 20 days, a daily 10-hourly snail shedding for cercariae was done to determine the infection rate, cercarial production per hour and survival period of infected snails. The study suggests that when parasite strains from a different geographical origin is used for infection, survival of infected snails increase, leading to an increased transmission potential. Although earlier literature had indicated that the Lake Victoria Biomphalaria sudanica is refractory to S. mansoni, we showed that all Ugandan Biomphalaria spp., including B. sudanica from all locations, were highly susceptible to the S. mansoni isolates. Thus if B. choanomphala, which is an efficient intermediate host in Lake Victoria, is given an opportunity to occupy Lake Albert, it will most likely be compatible with the Albertine S. mansoni parasites. Equally, if B. stanleyi, currently restricted to Lake Albert invades Lake Victoria, it is likely to act as an efficient intermediate host. Future work should concentrate on intraspecific population-level differences in compatibility.

We present an artificial infection experiment, which demonstrated the compatibility of Biomphalaria snails from Lake Victoria and Lake Albert with sympatric and non-sympatric Schistosoma mansoni isolates.Figure optionsDownload as PowerPoint slideHighlights
► Ugandan F1Biomphalaria were challenged with sympatric and non-sympatric Schistosoma mansoni isolates.
► All snails were highly susceptible to the S. mansoni isolates.
► The lifespan ranged 4–43 and 8–30 days for Albert and Victoria snails respectively.
► The general observation shows that the snails are compatible with both isolates.