MS Frontiers 2022 | What underlies the increased prevalence and incidence of multiple sclerosis in Tasmania?

Steve Simpson-Yap, PhD, MPH, University of Melbourne, Melbourne, Australia, explains the general factors influencing the prevalence and incidence of multiple sclerosis (MS). The factors underlying the former are incidence rate and case longevity. In the Greater Hobart cohort study of MS cases in Tasmania, Australia, prevalence and incidence were both shown to be increasing significantly. Immigration and emigration were adjusted for, making any changes in prevalence due to new diagnosis or symptom onset, and removal of cases due to mortality. It is not clear what the reasons are for the increased incidence of MS, because even though MS is a condition that usually has its onset in adulthood, the factors underlying MS risk date back to early childhood or even prenatal exposures. In turn, decade-long changes might have an effect (e.g., smoking, and BMI). Even the ‘slip-slap-slop’ campaign, an attempt to reduce melanoma due to sun exposure, may have increased vitamin D deficiency and consequently increased the incidence of autoimmune disorders, such as MS. This interview took place at the MS Frontiers 2022 congress in Swansea, UK.