Review Article

The Burden of Visceral Leishmaniasis in India: Challenges in Using Remote Sensing and GIS to Understand and Control

Table 1

Remote sensing and GIS application for visceral leishmaniasis (VL) in India: disease mapping and transmission modeling.

AimsMethods: remote sensing and GISConcept illustratedGeography and scaleData sourcesSoftware usedMajor findingsReference

The relationship between the incidence of VL and certain physioenvironmental factors was explored, using a combination of a geographical information system (GIS), satellite imagery, and data collected “on the ground”Supervised classification (Maximum Likelihood algorithm)Thiessen polygon, overlay, and index modelNortheastern Gangetic Plain, large scaleNOAA (AVHRR)ERDAS imagine v9.3, ArcGIS v9.2It was found that the presence of water bodies, woodland and urban, built-up areas, soil of the fluvisol type, air temperatures of 25.0–27.5 degrees C, relative humidities of 66%–75%, and an annual rainfall of 100–<160 cm were all positively associated with the incidence of VLBhunia et al., 2010 [13, 14]

To study the relationship between the incidence of kala-azar and topography and vegetation densityDigital elevation model (DEM), normalized difference vegetation index (NDVI)Overlay, spectral indices
India, large scaleSRTM, Landsat TM 5ERDAS imagine v9.3, ArcGIS v9.2(i) The results show significant variation in case diversity within the defined gradient.
(ii) Results also showed that most of the cases occurred in nonvegetative areas or low density vegetation zones.
Bhunia et al., 2010 [13, 14]

To delineate the potential hydrological relationship between the vector and
kala-azar transmission, the associations between inland water bodies, sand fly
prevalence, and Leishmania infections
Normalized difference pond index (NDPI), nearest neighbour analysis, radial basic function interpolationSpectral indices, geostatisticsLalganj and Hajipur block (Vaishali district, Bihar, India), medium to fineLandsat 5 TMERDAS Imagine v9.3, ArcGIS v9.2The higher moisture content of the surrounding areas of nonperennial rivers and lesser density of water bodies play an important role in the maintenance of sand fly density, promoting transmission of the diseaseBhunia et al., 2011 [25]

The spatial distribution of reported kala-azar cases in the
4 study periods of Muzaffarpur district, Bihar, India, during
the period from 1990 to 2008
Spatial analysisDatabase queriesMuzaffarpur district (Bihar, India), mediumArcGIS v9.2Within the district, the blocks with the highest number of cases shifted from east (1990–98) to west (1999–2008) that may correspond to a rise in herd immunity in western blocksMalaviya et al., 2011 [26]

The study focused on
examining disease distribution
in a kala-azar endemic region
in Bihar, India
Spatial analysis and standard deviation of ellipseGeostatisticsMuzaffarpur district (Bihar, India), fineArcGIS v9.2Mean centre of case observations within the district was identified which may aid to delineate ideal location to monitor and manage the deadly disease for epidemiological surveillance and control  
Standard deviation of ellipse (SDE) was drawn to understand the directional distribution of disease
Bhunia et al., 2012 [12]

To examine the relationship between LULC classes and their suitability for vector habitats in areas endemic for kala-azar at different spatial scalesThematic maps and satellite supervised classification (Maximum Likelihood algorithm)Overlay, buffering, land use/land coverVaishali and Muzaffarpur districts (Bihar, India), large to fine scaleAVHRR, MODIS, Landsat TM, LISS IVERDAS imagine v9.3, ArcGIS v9.2At national level, the fact that the highest information values were attained from areas associated with water bodies, closed shrub land, and urban areas indicates that these features are likely to contain vector habitats  
At state level, only a minor part of the total area seemed suitable for vector habitats. The highest information values were attained from bare areas or places with sparse or herbaceous vegetation, which indicates that these features support the presence of vectors  
At district level, high suitability for sand fly habitats was attributed to
marshy land, dry or moist fallow, and settlements, but areas associated with water-bodies, sandy areas, and plantations also indicated relatively high suitability  
At village level, the high suitability of some LULC types occupying grass/weeds covers land, marshy land, dry fallow, areas associated with water bodies and settlements. The plantation class assigned as medium potential for the sand fly habitat
Bhunia et al., 2012 [22]

NDVI: normalized difference vegetation index, WI: wetness index, SAVI: soil adjusted vegetation index, LST: land surface temperature, NDPI: normalized difference pond index, IRS: Indian remote sensing system, LISS: linear imaging self-scanning, TM: thematic mapper, AVHRR: advanced very high resolution radiometer, MODIS: moderate resolution imaging spectroradiometer.