From sketch to digital maps: A Geographic Information System (GIS) Model and Application for malaria control without the use of pesticides
Patricia Najera-Aguilar; Ramon Martinez-Piedra; Manuel Vidaurre-Arenas, Health Analysis and Information Systems (AIS), PAHO.
Introduction
The Geographic Information System (GIS) Model and Application “GIS-DDT” is a technical component of the “Regional program for the action and demonstration of sustainable alternatives on malaria vector control in Mexico and Central America”. It is being developed in cooperation with the Areas of Health Analysis and Information Systems (AIS), Sustainable Development and Environmental Health (SDE), and the malaria vector control programs from the participating countries, since 2003. This project has the support of the Global Environment Facility (GEF), the United Nations Environment Program (UNEP) and the North American Commission for Environmental Cooperation (CEC).
The objective of the GIS-DDT model and application is to standardize, integrate, compile and facilitate the interchange of digital cartographic infrastructure (data, methods and software) as a basis for analyzing geographic data about malaria vector control and DDT residuals. The main goal of this component is to contribute to the strengthening of the national technical capacities for malaria control.
GIS Model and Analysis Levels
The GIS-DDT model and application has two levels of analysis: Inter-community and Intra-community; they include the DDT-GEF general project indicators (categorized according to the health system’s framework of structure, process and results) that can be spatially analyzed and integrated in the GIS:
Preparation Phase
• Communities selection based on a risk-approach on malaria control model
• 4-6 weeks before the transference phase, local training and data collection
• Head Quarters-Local technical and methodological standardization for geographic data collection
Transference Phase
• In site workshop for adapting the GIS model to local conditions during three or four days
• Identification of lacking data
• Technical and methodological standardization for geographic coding schemes, data collection and analysis
Instrumentation Phase
• Prototype development following the GIS model to be used as a platform for data collection, surveillance, analysis and evaluation
• Development from four to eight weeks
Progress
The transference phase has been accomplished in six out of the eight countries: Costa Rica, Guatemala, Nicaragua, El Salvador, Panama and Honduras. They are developing the instrumentation phase. Belize is still in the preparation stage; and Mexico, as complex and large as it is, has designed and developed a web based GIS making an effort to standardize codes and criteria with other countries. Figure 1 illustrates a section of the original sketch map of the Panamanian community, Bisira, and its digital representation in a GIS map. The GIS map shows cartographic layers of houses with malaria cases, streets, rivers, and concentric buffers that allow the calculation of preventive treatments for dwellings located inside various radiuses, from 50 to 250 meters, around the houses with malaria cases.
Figure 1. From sketch to digital maps.
Preparation Phase Progress
• Belize asked for Global Positioning System (GPS) training and closer follow up in the GIS instrumentation.
Transference Phase Progress
• Workshops developed in six out of the eight countries using GIS and GPS technology is almost complete:
- Costa Rica, Dec 2004 (reinforcement, May 2005)
- Guatemala, Feb 2005
- Nicaragua, Mar 2005
- El Salvador, Apr 2005
- Panama, May 2005
- Honduras, May 2005
Instrumentation Phase Progress
• Most of the countries after the transference phase are developing the geo-referencing process of communities’ dwellings, mosquito breeding sites and landmarks, as well as the malaria data bases coding and standardization.
• Mexico has a web-based system.
The cartographic data collection, standardization and integration are in progress in most of the countries. Local health professionals and authorities are still surveying the settlements and mosquito breeding sites in the demonstration areas. Many health workers have expressed their satisfaction and empowerment feelings about having the chance to move forward and changing the way they usually collected and managed their data, from sketch mapping techniques to the use of GPS and GIS.
