EVALUATION OF LEPTOSPIROSIS CASES IN TÜRKIYE USING A GEOGRAPHIC INFORMATION SYSTEM

Abstract

Leptospirosis is a public health problem in Türkiye with cases occurring sporadically and occasionally in outbreaks.  In this study we aimed to retrospectively map leptospirosis cases in Rize Province, Türkiye during 2016-2022 using a geographic information system (GIS) in order to inform leptospirosis control efforts.  Data regarding numbers and locations of leptospirosis cases in the study province were obtained from an Infectious Disease Surveillance and Early Warning System and entered into GIS software and examined for spatial patterns.  A total of 97 subjects were included in the study, 59% males.  The mean (±standard deviation) age of study subjects was 59 (±11) years.  During the study period, the year with the largest number of leptospirosis cases was 2018 (n = 37) (p<0.001) and the month of the year during the study period with the most cases was September (n = 32) (p<0.001).  The incidence of cases was highest during June-October (n = 85) (p<0.001).  The districts in Rize Province where the most leptospirosis cases occurred were the 3 contiguous coastal districts of Merkez (n = 31), Çayeli (n = 16) and Pazar (n = 12) (p<0.001).  Cases were also reported in Güneysu District (n = 11) (p<0.001).  The other cases of leptospirosis were distributed sporadically.  In summary, leptospirosis cases in Rize Province occurred primarily in clusters in 3 contiguous provinces during the study period and were more common during 2018 and during September.  We conclude these patterns need to be taken into consideration by efforts to reduce the incidence of leptospirosis in the study area.  Further studies are needed to determine why there are more cases in these specific districts during September and if they have preventable origins in order to improve leptospirosis control efforts in Rize Province, Türkiye.