Understanding the global distribution of lymphatic filariasis (LF) is essential for the elimination of LF and for undertaking surveillance activities once control efforts have stopped. However, until now, there has not been a global map of LF distribution.
A new paper in Parasites & Vectors discusses the research behind the first global map of LF distribution and transmission limits developed by the Global Atlas of Helminth Infection (GAHI) and its partners. LF is one of the NTDs targeted for global elimination by 2020 and geographically targeted and sustained control will be required to achieve it. This first global map can help evaluate the progress of interventions and guide surveillance activities.
The global map highlights a highly heterogeneous distribution in sub-Saharan Africa, with more widespread transmission in West Africa. Transmission also occurs across much of south and south-east Asia and the Pacific, but only occurs in isolated foci in South America.
To develop the map the research team conducted a systematic search and assembly of data on the prevalence of LF. They used the various environmental and climatic data together with boosted regression trees (BRT) modelling to predict the transmission limits of LF.
First author, Jorge Cano, says, “This work is the result of a joint effort to develop the most comprehensive repository of survey data on lymphatic filariasis infection and to better understand the global limits of transmission. It provides a key resource for global efforts to achieve the elimination of this vector-borne disease by 2020. The assembled data maps and model predictions will help track progress and increase the cost-effectiveness of surveillance activities post-control.
Consistent with GAHI’s open access approach, the assembled data and developed maps will be made publicly available on our website.
Our next challenge is to investigate the spatiotemporal distribution of lymphatic filariasis and to determine the contribution of scaling-up intervention and socio-economic development on changes in disease distribution.”
The research was supported by the Wellcome Trust, Bill & Melinda Gates Foundation, and GlaxoSmithKline, as part of GAHI’s efforts to develop geographical resources for neglected tropical diseases.
Authors:
Jorge Cano Ortega
Maria Rebollo, Task Force for Global Health
Nick Golding, University of Oxford
Rachel L Pullan
Thomas Crellen, Imperial College London
Anna Soler, London School of Hygiene & Tropical Medicine
Louise A Kelly-Hope, Liverpool School of Tropical Medicine
Steve Lindsay, Durham University
Simon I Hay, University of Oxford
Moses J Bockarie, Liverpool School of Tropical Medicine
Simon J Brooker