The use of GIS in leprosy control.

Mapping of diseases has, since John Snow produced his famous cholera maps of London in 1854, been recognised as an essential tool in public health. A Geographical Information System (GIS) is more than mapping diseases: it manages, analyses and presents data that are linked to geographical locations. GIS enables creation of maps and can present data on national and regional level, but also on very detailed levels, such as households. Beyond administrative boundaries it can also present variables such as land use type and altitude. Its specific strength is that it can visualise, establish relationships and analyse different features that share the same location. The combination of person, time and space makes GIS a powerful epidemiological tool for disease prevention and control. In the last decade, epidemiologists increasingly recognised the importance of GIS. GIS has been applied in research, prevention and control of several infectious diseases such as malaria, tuberculosis, and HIV/AIDS. The added value of GIS for leprosy control programmes has not yet been recognised by all. Among people involved in leprosy control one finds those advocating the use of GIS and those with a critical attitude towards it as they see constraints in its implementation and no clear benefits. There are some examples of control programmes that use GIS and WHO has also been promoting its use. However, programmes often use GIS only on an ad-hoc basis. In this editorial we want to discuss GIS in leprosy control: how it has been used so far, other possible applications, and its added value and limitations. The main areas of application of GIS in disease control are: (1) research to generate new knowledge; (2) public health to design focussed interventions; and (3) management to plan and monitor control programmes. Apart from these three areas there is an important role for GIS in (4) advocacy.