Prediction of hookworm prevalence in southern India using environmental parameters derived from Landsat 8 remotely sensed data. Issue 1 (January 2020)

• Record Type: Journal Article
• Authors: Kulinkina, Alexandra V.; Sarkar, Rajiv; Mohan, Venkata R.; Walz, Yvonne; Kaliappan, Saravanakumar P.; Ajjampur, Sitara S.R.; Ward, Honorine; Naumova, Elena N.; Kang, Gagandeep
• Is Part Of: International journal for parasitology. Volume 50:Issue 1(2020)
• Page Start: 47
• Page End: 54
• Publication Date: 2020-01
• Subjects: Hookworm -- Soil-transmitted helminths -- Spatial modelling -- India -- Remote sensing; Parasitology -- Periodicals; Parasitology -- Periodicals; Parasitologie -- Périodiques; Parasitology; Periodicals; Electronic journals; 571.999
• DOI: 10.1016/j.ijpara.2019.10.001
• Languages: English
• ISSNs: 0020-7519

Abstract

Graphical abstract: Highlights: Environmental conditions are important determinants of hookworm transmission. Remotely sensed data are commonly used for disease risk profiling. Elevation and slope were the most important predictors of hookworm transmission. A small buffer radius around village centroids (300 m) produced the best model performance. Remotely sensed data acquired in dry and rainy seasons had similar model performance. Abstract: Soil-transmitted helminth infections propagate poverty and slow economic growth in low-income countries. As with many other neglected tropical diseases, environmental conditions are important determinants of soil-transmitted helminth transmission. Hence, remotely sensed data are commonly utilised in spatial risk models intended to inform control strategies. In the present study, we build upon the existing modelling approaches by utilising fine spatial resolution Landsat 8 remotely sensed data in combination with topographic variables to predict hookworm prevalence in a hilly tribal area in southern India. Hookworm prevalence data collected from two field surveys were used in a random forest model to investigate the predictive capacity of 15 environmental variables derived from two remotely sensed images acquired during dry and rainy seasons. A variable buffer radius (100–1000 m) was applied to the point-prevalence locations in order to integrate environmental conditions around the village centroids into the modelling approach and understand where transmission is more likely. Elevation and slope were the most important variables in the models, with lower elevation and higher slope correlating with higher transmission risk. A modified normalised difference water index was among other recurring important variables, likely responsible for some seasonal differences in model performance. The 300 m buffer distance produced the best model performance in this setting, with another spike at 700 m, and a marked drop-off in R 2 values at 1000 m. In addition to assessing a large number of environmental correlates with hookworm transmission, the study contributes to the development of standardised methods of spatial linkage of continuous environmental data with point-based disease prevalence measures for the purpose of spatially explicit risk profiling.