Interactive Effects of Climatic Changes and Environmental Factors on Distribution of Cutaneous Leishmaniasis in Kashan City, Central Iran, from 2007 to 2019

Climate change and environmental factors are two factors affecting the ecosystem and life cycle of vector insects. In this study, the effects of climatic elements and environmental factors on cutaneous leishmaniasis in Kashan were studied.

This study has adopted an analytical‑descriptive method. Climatic data were compared with 3949 cases of cutaneous leishmaniasis from 2007 to 2019 using SPSS 22 software and Pearson correlation. Furthermore, the prevalence of cutaneous leishmaniasis cases in Kashan city was displayed on the land use maps, land cover map, rainfall map, thermal classification map, and digital elevation model and then was investigated.

Pearson correlation analysis showed a negative correlation between cutaneous leishmaniasis cases and spring temperature while a positive correlation with total rainfall and winter rainfall was observed. Investigating the spatial distribution of cases of cutaneous leishmaniasis in Kashan city was observed that the frequency of this disease was higher near Kashan desert belt from Abuzeidabad to Abshirin, the landfill areas, around the agricultural fields, the main roads, and the outskirts of the city.

The frequency of cutaneous leishmaniasis has a significant negative correlation with reduction of temperature in spring to the desired level for the activity of sandflies. Rainfall has also caused a significant increase of this disease. Autumn has the most cases and spring the least ones. In the spatial distribution of the disease, a clear relationship with the desert areas, where the disease reservoir mice were living, and the agricultural fields, where sandflies reproduced and had activity, was observed.