The effect of environmental parameters on the incidence of Shigella outbreaks in Yazd province, Iran

Abstract

Climate changes have a profound effect on human health, especially when infectious diseases are concerned. Variable factors including temperature, precipitation, and relative humidity directly influence the magnitude and frequency of water-borne pathogen transfers. In this study, we determined the long-term temporal trends and seasonal patterns of shigellosis and evaluated the effects of demographic and climatic factors on its incidence in Yazd province, Iran, during 2012 through 2015. The incidence of shigellosis was highest among patients in the age group of 6–20 years and peaked in every summer of the years studied, especially during August. Furthermore, there was a significant association between climatic variables (such as monthly temperature, humidity, and atmospheric dust) and the incidence of shigellosis. However, contrary to expectations, rainfall did not affect incidence of the disease. The transmission of Shigella to humans is a complex ecological process. Socio-economic factors and lifestyle behaviours need to be addressed in future studies.

Climate change and human health in the Eastern Mediterranean and Middle East: Literature review, research priorities and policy suggestions

“…As with exposure to extreme heat, groups that are particularly vulnerable to the exposure of high dust concentrations include very young children and older adults (due to underdeveloped or deteriorating immunity, respectively), as well as people with chronic cardiopulmonary diseases. Studies in Iran have reported a link between temperature, humidity, atmospheric dust and peaks of shigellosis cases in summer months ( Aminharati et al, 2018 ). Furthermore, research performed in the city of Ilam (western Iran) revealed that the concentration of bio-aerosols in the environment is elevated during dust storms ( Amarloei et al, 2020 ).…”