Abstract

OBJECTIVES: The prevalence of multiple sclerosis (MS) in the Persian Gulf countries has been significantly increasing during the past decades. This study was conducted for investigating the prevalence and incidence of MS in Northeast Iran (Khorasan Razavi province). METHODS: This cross-sectional study was conducted during 1 January 1988 and 23 September 2018. All patients with a clinically definite diagnosis of MS according to the McDonald criteria (2005) and MRI along with the medical diagnosis, recorded in the Khorasan MS society, were considered for calculation of crude and age-standardized prevalence, and incidence rates of MS. The periodic incidence rates were calculated based on the year of onset of MS. Also, we calculated gender ratios for prevalence and incidence rates. RESULTS: The mean age-standardized prevalence and incidence rates of MS in the Khorasan Razavi were 8.69 (95 CI 8.05-9.41) per 100,000 (3.99 (95 CI 3.39-4.74) for males, 13.49 (95 CI 12.37-14.76) for females). Age-standardized prevalence was 48.87 (95 CI 48.37-49.35) per 100,000 (22.47 (95 CI 22.01-22.93) for males, 75.65 (95 CI 74.80-76.51) for females). Also, the mean incidence and prevalence for Mashhad County as capital of province were 11.38 and 59.09 per 100,000 populations, respectively. The female/male ratio was 3.33 for all age groups. CONCLUSION: Our results showed that this region is a high-risk area for MS like central region of Iran. Our results revealed that the prevalence and incidence of MS in the study area have increased during the recent decades with a sharp slope.