Ongoing increase in incidence and prevalence of multiple sclerosis in south-eastern Iran: A three decade study

Abstract

Background: Prevalence of multiple sclerosis has been increased during the last decades throughout the world. Epidemiological studies could improve our understanding relating to its intrinsic and extrinsic causes. Objectives: The current study has been conducted to determine the epidemiological features of MS in southeastern Iran which is a semi-tropical area with different ethnicities. Methods: This longitudinal descriptive study was carried out in south-eastern Iran, based on information of MS patients registered at Zahedan University of Medical Sciences database from 1990 to 2020. Results: A total of 1045 cases were enrolled into the study. The age-standardized prevalence ratio of MS increased to 42.2/100,000 population by 2020. These figures showed increasing trends both in females and males and reached to 61.5 and 22.6 per 100,000 population, respectively by the year 2020. Likewise, the total incidence rate grew to its maximum amount of 4.5 in 2015. Female incidence also revealed an upward trend and peaked in 2016 to 6.4 while male incidence rate reached at its highest level of 1.8 in 2009. Conclusion: MS prevalence ratios and incidence rates in south-eastern Iran have been increasing steadily, especially in women during the last three decades. The south-eastern part of Iran should be considered a high-risk region.