Data from: Epidemiological interactions between urogenital and intestinal human schistosomiasis in the context of praziquantel treatment across three West African countries

Background: In many parts of sub-Saharan Africa, urogenital and intestinal
schistosomiasis co-occur, and mixed species infections containing both
Schistosoma haematobium and S. mansoni can be common. During co-infection,
interactions between these two species are possible, yet the extent to
which such interactions influence disease dynamics or the outcome of
control efforts remains poorly understood. Methodology/Principal Findings:
Here we analyse epidemiological data from three West African countries
co-endemic for urogenital and intestinal schistosomiasis (Senegal, Niger
and Mali) to test whether the impact of praziquantel (PZQ) treatment,
subsequent levels of re-infection or long-term infection dynamics are
altered by co-infection. In all countries, positive associations between
the two species prevailed at baseline: infection by one species tended to
predict infection intensity for the other, with the strength of
association varying across sites. Encouragingly, we found little evidence
that co-infection influenced PZQ efficacy: species-specific egg reduction
rates (ERR) and cure rates (CR) did not differ significantly with
co-infection, and variation in treatment success was largely geographical.
In Senegal, despite positive associations at baseline, children with S.
mansoni co-infection at the time of treatment were less intensely
re-infected by S. haematobium than those with single infections,
suggesting competition between the species may occur post-treatment.
Furthermore, the proportion of schistosome infections attributable to S.
mansoni increased over time in all three countries examined.
Conclusions/Significance: These findings suggest that while co-infection
between urinary and intestinal schistosomes may not directly affect PZQ
treatment efficacy, competitive interspecific interactions may influence
epidemiological patterns of re-infection post-treatment. While
re-infection patterns differed most strongly according to geographic
location, interspecific interactions also seem to play a role, and could
cause the community composition in mixed species settings to shift as
disease control efforts intensify, a situation with implications for
future disease management in this multi-species system.