1. Ram Chandra Bajpai Biostatistician, NACO, New Delhi
Geographic Information System (GIS) in Public Health : Issues and Challenges
Ram Chandra Bajpai
Biostatistician, NACO, New Delhi

2. Background
According to Hippocratic ( BC) view it was observed that certain diseases tend to occur in some locations which explain that health and disease stressed the relationship between human beings and his environment.
John Snow, a British Physician (1854) first who shaped the maps to find out hidden causes behind the massive outbreak for cholera deaths in Soho districts of London and showed that the source of this disease was contaminated water pump.
The first operational GIS was used by Dr. Roger Tomlinson (1960) to determine the land capability for rural Canada by mapping information about soil, agriculture, recreation, wildlife, waterfowl, forestry and land. It was called ‘Canada Geographic Information System (CGIS)’.
By the end of 20th century, GIS is widely recognized by public agencies, research laboratories, academic institutions, private industry and public utilities as a useful tool for supporting urban and provincial resource planning and management.

3. Geographic Information System (GIS)
It is a computerized system for input, storage, management, display and spatial analysis of data that can be precisely linked to a geographical location.
‘Smartmap’ is a another term that used as a synonym for GIS that allows users to create interactive queries, analyze spatial information and edit data.
GIS datasets come as layers – there can be a layer for rivers, a layer for roads, and a layer for zip codes – all within a particular geographical boundary.
Each GIS layer has two views: a map view and a data view
The map view tells the visual representation of data
The data view can be used to edit data.

4. Models of GIS It consist of two models:
Vector data model represents space as points, lines or polygons that are geographically referenced.
Raster data model divides a space into equal sized pixels with attributes recorded as a numeric value for each pixel.
Both models fulfil the analytical and representational requirements of a GIS and should be based on nature of data and output required when choosing a GIS.

5. Applications of GIS in Public Health
Mapping the disease incidence/prevalence over some geographic area to see the trends as well as the present situation.
GIS technique provides an organize and link datasets that can help the public health practitioners to plan more cost-effective innervations.
Public health researchers are able to find out the estimation of spatial variation of disease, determination of risk factors disease, and improved delivery of health services.
Public health departments can use GIS to create a link between department of Transportation for information about traffic flow and accidents, quick ambulance services to hospital emergency rooms.
GIS technology can be an extremely effective tool to help community decision makers visualize and understand a public health problems and provide an ability to quick responses to questions raised in a community by preparing a maps.

6. Extended Applications
Monitor health status to identify community problems.
Diagnose and investigate health problems and hazards in the community.
Mobilize community partnerships and action to identify and solve health problems.
Enforce laws and regulations that protect health and insure safety.
Evaluate effectiveness, accessibility, and quality of personal and population based health issues.
Develop policies and plans that support individual and community health effects.
Research for new insights and innovative solutions to health problems.

7. Available Softwares Free GIS Softwares Commercial Softwares
EpiMap: developed by Centers for Disease Control and Prevention (CDC) in collaboration with the World Health Organization (WHO).
HealthMapper: designed and developed jointly by WHO and UNICEF specially for public health practitioners.
GeoDa[TM]: developed by University of Illinois is a user-friendly for non-GIS specialists.
Commercial Softwares
ArcView/ArcGIS: produced by ESRI, Inc. and represents one of the standards in the industry. Extensively used by researchers.
MapInfo: developed by MapInfo and this is also widely used, less in cost as well as in capability with ESRI products.

8. Limitations
Community health planning and other public health applications remain a relatively underdeveloped marketplace role for GIS.
Non-availability of state/district level maps that are essential for epidemiologist to understand the disease outbreak.
GIS training is not easily available for health professionals and cost of training is very high.
GIS software are not cost-effective and a new iterations released about every 18 months.
Non-availability of required data in both developing and developed nations due to national security, confidentiality etc.

9. Current Scenario Successfully used in Malaria Research Control.
World wide used in HIV/AIDS prevention and its research.
Public health researchers are using GIS technology to find out the hidden causes of a disease and its association with Environment.
Almost all developed countries have their geo-health database while developing nations are struggling with GIS technocrats.
In India, GIS technology is also using by some government departments but not much used in public health research.
Less number of studies are available using GIS technology to know the spatial pattern of a disease in India.

10. Conclusions
GIS is an effective tool to understand the disease pattern, trend and its determinants.
GIS is very much useful in public health planning, policy making, disease control and research.
Public health applications of GIS technology are still in early stage specially in India.
A huge fund is required to use GIS in public health departments.
Carefully incorporate epidemiological and statistical principles to draw false conclusions from GIS maps.

11. Thanks