title: Dynamic Relations between Incidence of Zoonotic Cutaneous Leishmaniasis and Climatic Factors in Golestan Province, Iran.
abstract: BACKGROUND
  Zoonotic Cutaneous Leishmaniasis (ZCL), an important public health problem in Iran, is sensitive to climate conditions. This study aimed to examine dynamic relations between the climate factors and incidence of ZCL in Golestan Province, northern Iran during 2010-2012.
  
  
  METHODS
  Data of monthly climatic factors, including temperature variables, relative humidity variables, evaporation, total rainfall, and number of freezing and rainy days together with monthly ZCL incidence were used. Spear-man rank correlation was carried out to explain associations between the monthly ZCL incidence rate and climate factors at 0, 1, 2, 3 and 4 months lagged periods. Pearson's correlation analysis was conducted to examine the type and strength of relationships between the spatially averaged climate factors and ZCL incidence rate in district level. Stepwise multiple regression was used to find the best combination of independent climatic variables, which predict the ZCL incidence.
  
  
  RESULTS
  Spearman correlation analysis indicated that the highest correlations between climate factors and monthly ZCL incidence were established when the climate time-series lagged the ZCL incidence series, especially two month prior to disease incidence. Based on the results of the both Spearman rank correlation and Pearson correlation analyses, ZCL incidences in Golestan Province tend to be more prevalent in areas with higher temperature, lower relative humidity, lower total rainfall, higher evaporation and lower number of rainy days. The results of stepwise regression analysis indicated that minimum temperature, mean humidity, and rainfall had considerable effect on ZCL incidence.
  
  
  CONCLUSIONS
  Climate factors are major determinants of ZCL incidence rate in Golestan Province and such climate conditions provide favourable conditions for propagation and transmission of ZCL in this endemic area.
authors.affiliation: Communicable Diseases Management Center, Ministry of Health and Medical Education, Tehran, Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Shirzadi
authors.affiliation: Department of Geo-spatial Information System (GIS), Center of Excellence in GIS, K. N. Toosi University of Technology, Tehran, Iran.
authors.forename: Abolfazl
authors.initials: A
authors.lastname: Mollalo
authors.affiliation: Department of Medical Entomology and Vector Control, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Yaghoobi-Ershadi
keywords: Climate factors; Correlation analysis; GIS; Iran; Zoonotic Cutaneous Leishmaniasis (ZCL)