GAHI - Global Atlas of Helminth Infections

GAHI shows the geographical distribution of neglected tropical diseases (spatial epidemiology) transmitted by worms: soil-transmitted helminthiasis, schistosomiasis, and lymphatic filariasis. All GAHI resources are available on an open access basis.

Inspiration for this project comes from the work of the American parasitologist Norman Stoll. Dr Stoll researched worm infections, including work in China, Panama and Puerto Rico, in the first half of the 20th century.

Building on Stoll's work, in 1998 the WHO Collaborating Centre for the Epidemiology of Intestinal Parasites at the University of Oxford and WHO launched an initiative aimed at collating the available survey data as both a database and graphical tool. This had the twofold aim of describing, where possible, the prevalence across Africa and highlighting areas for which further information is required.

Main areas of recent and current research include:

• Defining the global climatic limits of STH and LF
• Estimating the population at risk of infection and morbidity caused by STH
• Estimating the global distribution of trachoma
• Defining the pre-intervention distribution of NTDs, including STH, LF and trachoma
• Understanding the factors associated with changes in infection and with the persistence of transmission
• Modelling the contextual factors influencing the transmission of NTDs, including access to water and sanitation

We have also worked with the Task Force for Global Health to develop the NTD Mapping Tool, and the International Trachoma Initiative to develop the Global Atlas of Trachoma.