Updated Systematic Review on Epidemiology of Multiple Sclerosis in Iran: Central Accumulation and Possible Role for Industrial Pollution

Background: In spite of previous studies, recent epidemiological studies estimated most of the Iran’s provinces as intermediate to high risk areas. In the present study, we aimed to update our previous research and marshal newly published works on epidemiology of MS disease in Iran during recent five years.

Methods: For literature search, a comprehensive electronic search was performed on PubMed, EBSCO and Web of Sciences and regional data bases. Our search process in electronic databases was performed using the following search items: ‘multiple sclerosis and Iran’, ‘multiple sclerosis and population’, ‘multiple sclerosis and epidemiology’, ‘multiple sclerosis and prevalence’, ‘multiple sclerosis and incidence’.

Results: MS distribution across Iran has a range from 7.4 to 101.39 per 100,000. Twenty one provinces of Iran are classified in high risk of MS disease (>25/100,000); 9 provinces in intermediate risk (5-25/100,000) and one province in low risk (<5/100,000).

Conclusion: the reason for the pattern of the current MS distribution in Iran is not explainable by the traditional gradient theory. The disease is seemingly more prevalent in central parts of Iran; to date, accumulation of MS in central parts of Iran has not been clearly reported.