Mapping the human helminthiases: advances and gaps in neglected disease surveillance

Helminthiases are a class of neglected tropical diseases that affect at least one billion people worldwide, with a disproportionate impact in resource-poor areas with limited disease surveillance. Geospatial methods can offer valuable insights into the burden of these infections, particularly given that many are subject to strong ecological influences on the environmental, vector-borne, or zoonotic stages of their life cycle. In this study, we screened 6,829 abstracts and analyzed 485 studies that use maps to document, infer, or predict transmission patterns for over 200 species of parasitic worm. We found that quantitative mapping methods are increasingly used in medical parasitology, drawing on One Health surveillance data from the community scale to model geographic distributions and burdens up to the regional or global scale. However, we found that the vast majority of the human helminthiases may be entirely unmapped, with research effort focused disproportionately on a half-dozen infections that are targeted by mass drug administration programs. Entire regions were also surprisingly under-represented in the literature, particularly southern Asia and the Neotropics. We conclude by proposing a shortlist of possible priorities for future research, including several neglected helminthiases with a burden that may be substantially underestimated.