title: Correlation Assessment of Climate and Geographic Distribution of Tuberculosis Using Geographical Information System (GIS).
abstract: BACKGROUND
  Tuberculosis (TB) spread pattern is influenced by geographic and social factors. Nowadays Geographic Information System (GIS) is one of the most important epidemiological instrumentation identifying high-risk population groups and geographic areas of TB. The aim of this study was to determine the correlation between climate and geographic distribution of TB in Khuzestan Province using GIS during 2005-2012.
  
  
  METHODS
  Through an ecological study, all 6363 patients with definite diagnosis of TB from 2005 until the end of September 2012 in Khuzestan Province, southern Iran were diagnosed. Data were recorded using TB- Register software. Tuberculosis incidence based on the climate and the average of annual rain was evaluated using GIS. Data were analyzed through SPSS software. Independent t-test, ANOVA, Linear regression, Pearson and Eta correlation coefficient with a significance level of less than 5% were used for the statistical analysis.
  
  
  RESULTS
  The TB incidence was different in various geographic conditions. The highest mean of TB cumulative incidence rate was observed in extra dry areas (P= 0.017). There was a significant inverse correlation between annual rain rate and TB incidence rate (R= -0.45, P= 0.001). The lowest TB incidence rate (0-100 cases per 100,000) was in areas with the average of annual rain more than 1000 mm (P= 0.003).
  
  
  CONCLUSIONS
  The risk of TB has a strong relationship with climate and the average of annual rain, so that the risk of TB in areas with low annual rainfall and extra dry climate is more than other regions. Services and special cares to high-risk regions of TB are recommended.
authors.affiliation: Dept. of Epidemiology, Faculty of Medicine, Dezful University of Medical Sciences, Dezful, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Beiranvand
authors.affiliation: Dept. of Epidemiology, Social Determinants of Health Research Center, Kurdistan University of Medical Sciences, Sanandaj, Iran.
authors.forename: Asrin
authors.initials: A
authors.lastname: Karimi
authors.affiliation: Dept. of Epidemiology, Faculty of Health, Ilam University of Medical Sciences, Ilam, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Delpisheh
authors.affiliation: Research Center for Prevention of Psychosocial Injuries, Ilam University of Medical Sciences, Ilam, Iran.
authors.forename: Kourosh
authors.initials: K
authors.lastname: Sayehmiri
authors.affiliation: Dept. of Environmental Health, Faculty of Health, Ilam University of Medical Sciences, Ilam, Iran.
authors.forename: Samira
authors.initials: S
authors.lastname: Soleimani
authors.affiliation: Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Shahnaz
authors.initials: S
authors.lastname: Ghalavandi
keywords: Annual rain; Climatic processes; Geographic information systems; Tuberculosis