Environmental Variables Associated with Distribution of Canine Visceral Leishmaniasis in Dogs in Ardabil Province, Northwestern Iran: A Systematic Review

Background: Visceral leishmaniasis (VL) is a zoonotic disease that currently occurs in some parts of Europe, Asia, Africa, and America. This study aimed to determine the distribution of the canine visceral leishmaniasis in dogs (Canis lupus familiaris) in northwestern Iran. Methods: The data were collected from 1994 to 2018 in Ardabil Province from electronic databases. An extensive literature search was conducted in different international and national databases, including Cochrane, MEDLINE/PubMed, Scopus, Web of Science, and Iran Medex to find articles with the words "visceral leishmaniasis in Ardabil" in their titles, and "canine visceral leishmaniasis in Ardabil" or "accidental reservoir hosts of visceral leishmaniasis in Ardabil" in their subtitles, irrespective of the type and duration of study. The GIS software and MaxEnt model were used to determine the ecologically suitable niches for the disease. Results: In total, 9088 dogs were examined, and the overall prevalence rate of CVL in dogs was estimated to be 14.56%. The most ecologically suitable areas of CVL occurrence were identified in four hotspots in Mesh-kinshahr, Germi, and two spots in Parsabad counties. The results of jackknife test showed that the environmental and climate variables with the highest gain, when used in isolation, were Isothermality, Bio3, Bio13, and Bio 4. Conclusion: A widely epidemic CVL has emerged among dogs, making a lot of risks on inhabitants of this area and increasing the probability of an outbreak of VL in humans.