Does the Multiple Sclerosis (MS) Map need to change again? An update of MS prevalence in Mazandaran province of Iran in 2018.

Abstract

Background: Information of Previous studies on the prevalence of MS, including our study conducted twelve years ago, used to shape global prevalence map of MS. According to those results, Iran placed in medium-prevalence MS region in the world Atlas of MS 2013.This study aimed to investigate the prevalence of MS in Mazandaran province after twelve years and the need for possible changes in the global map of the prevalence of MS. Methods: We included all MS patients living in Mazandaran province in 2018 in this descriptive cross-sectional study. We updated our pre-existing registration questionnaires which included demographic information and medical data of MS patients by interview. We obtained the demographic profile of Mazandaran province from the most recent census in 2016 and the National Civil Registry of the Mazandaran province for calculating prevalence of MS. Results: The total number of MS patients in Mazandaran was 2418 (25.8% male and 74.2% female) with a female to male ratio of 2.9. Based on the local population of 3332556, (50.4% male and 49.6% female), this study showed a prevalence of 72.5 per 100,000 for MS in this region. The prevalence of this disease by gender was 37.1 per 100,000 for men and 108.5 per 100,000 for women. The mean (SD) age of the patients at the time of the study was 38.5 (10.1) years with a minimum of 15 and a maximum of 75 years. The most common type of MS was Relapsing-Remitting MS with 86%. Conclusions: All recent studies showed significant upward trend in the prevalence of MS around the world. Based on the results of our study and many other studies in Iran, the Atlas of MS prevalence map needs to be update. Iran's status should be changed to the high-prevalence of MS in the new Atlas. Due to the increasing prevalence of MS, we suggest an adjustment in the Global MS Prevalence Scale.

Age and sex-adjusted incidence and yearly prevalence of multiple sclerosis (MS) in Mazandaran province, Iran: An 11-years study

“…MS cases increased in Mazandaran province over the past 11 years, with the highest prevalence age groups of 20 to 40 years old. The annual incidence of the disease has increased over the last 11 years with a mild variation in different years, and there has been a 3.6-fold increase in the cumulative prevalence of MS from 20.1 [ 3 ] in 2007 to 72.5 per 100,000 in 2018 [ 12 ]. There was an increase in female to male ratio of MS incidence during the study period.…”

“…Subsequent studies resulted in the correction of the place of Iran and placed it in the medium-risk prevalence area [ 28 ]. However, according to the results of recent studies, Iran may need to be placed in the high-risk prevalence area for MS [ 12 , 19 ].…”

“…Therefore, Mazandaran has a heterogeneous population and the third-highest population density after Tehran and Gilan provinces in Iran [ 11 ]. We can see a four-times increase in the prevalence of MS in Mazandaran in a period of eleven years from the initial study in this province in 2008 [ 3 ] to the recent study in 2018 [ 12 ].…”

Medical records and multiple sclerosis: A population-based case–control study

“…According to our previous ndings, the incidence of MS in Mazandaran province has increased in recent years, and the increase is observed in both genders and individuals with positive family history. Although the interaction between genetic and environmental factors has played a role in enhancing its incidence rate, environmental factors seem to play a more potent role (5)(6)(7). The present study aimed to determine the role of each factor and their effect size on the MS development in a case-control study.…”