Potential Effects of Climatic Parameters on Human Brucellosis in Fars Province, Iran, during 2009-2015

Document Type: Original Article(s)

Authors

1 Department of Community Medicine, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran

2 Department of Physical Geography, University of Sistan and Baluchestan, Zahedan, Iran

3 Department of Health Education and Promotion, Shiraz University of Medical Sciences, Shiraz, Iran

4 Public Health Specialist, Shiraz University of Medical Sciences, Shiraz, Iran

Abstract

Background: Human brucellosis is widespread in Fars province. The present study aimed to investigate the effect of climate on its incidence and determine the areas prone to the infection.Methods: Monthly meteorological data and the incidence rate of human brucellosis during 2009-2015 were collected and their correlation was studied using Pearson's correlation coefficient. Additionally, the multiple regression method and multi-layer perceptron neural network model were used to predict the incidence of human brucellosis.Results: Pearson's regression analysis, on monthly basis, showed a significant indirect correlation between the incidence of human brucellosis (with a time lag of up to 5 months) and climatic parameters (minimum temperature: -0.72 and evaporation: -0.73) in Abadeh (Fars, Iran). Moreover, there was a significant direct correlation (P<0.001) between the incidence of human brucellosis and the maximum relative humidity (+0.67) and rainfall (+0.48). The incidence of human brucellosis in Abadeh was predicted by using artificial neural network models (4 layers, 4 neurons in each layer), the Levenberg-Marquardt training algorithm, and Sigmoid transfer function. It was determined that a correlation rate of 0.89 in the training level and 0.8 in the test level (with the lowest error rate) were the best values in multi-layer perceptron modeling.  Conclusion: Climatic parameters are important factors in determining the incidence rate of human brucellosis in Fars province. Climate conditions provide a favorable environment for the spread of human brucellosis in this area.

Keywords