Determining the spatial distribution of environmental and socio-economic suitability for human leptospirosis in the face of limited epidemiological data

CRISTALDI, MAXIMILIANO; THIBAULT, CATRY; POTTIER, AURÉA; HERBRETEAU, VINCENT; ROUX, EMMANUEL; JACOB, PAULINA; PREVITALI, ANDREA

Infectious diseases of poverty

Springer nature

Año: 2022

2049-9957

Background: Leptospirosis is among the leading zoonotic causes of morbidity and mortality worldwide. Knowledgeabout spatial patterns of diseases and their underlying processes have the potential to guide intervention efforts.However, leptospirosis is often an underreported and misdiagnosed disease and consequently, spatial patterns of thedisease remain unclear. In the absence of accurate epidemiological data in the urban agglomeration of Santa Fe, weused a knowledge-based index and cluster analysis to identify spatial patterns of environmental and socioeconomicsuitability for the disease and potential underlying processes that shape them.Methods: We geocoded human leptospirosis cases derived from the Argentinian surveillance system during theperiod 2010 to 2019. Environmental and socioeconomic databases were obtained from satellite images and publiclyavailable platforms on the web. Two sets of human leptospirosis determinants were considered according to the levelof their support by the literature and expert knowledge. We used the Zonation algorithm to build a knowledge-basedindex and a clustering approach to identify distinct potential sets of determinants. Spatial similarity and correlationsbetween index, clusters, and incidence rates were evaluated.Results: We were able to geocode 56.36% of the human leptospirosis cases reported in the national epidemiologicaldatabase. The knowledge-based index showed the suitability for human leptospirosis in the UA Santa Fe increasedfrom downtown areas of the largest cities towards peri-urban and suburban areas. Cluster analysis revealed down-town areas were characterized by higher levels of socioeconomic conditions. Peri-urban and suburban areas encom-passed two clusters which differed in terms of environmental determinants. The highest incidence rates overlappedareas with the highest suitability scores, the strength of association was low though (CSc r = 0.21, P < 0.001 and EScr = 0.19, P < 0.001).Conclusions: We present a method to analyze the environmental and socioeconomic suitability for human lepto-spirosis based on literature and expert knowledge. The methodology can be thought as an evolutive and perfectiblescheme as more studies are performed in the area and novel information regarding determinants of the disease