Increased incidence of multiple sclerosis in the Veneto region, Italy.

Background: To what extent the progressive increase in the incidence of multiple sclerosis (MS) observed in the province of Padova over the period 1970–1999 was an expression of a real increased risk of developing MS remained unclear. Objective: The objective of this paper is to update the epidemiological figures of MS and probe whether the risk of having MS has increased in the province of Padova during the decade 2000–2009. Methods: All patients born in Italy and having a diagnosis of MS or possible MS identified through analysis of all available sources of information were included in the study. The incidence and prevalence rates between 2000 and 2009 were obtained and compared with our previously published data. Results: On 31 December 2009, the overall prevalence was 139.5/100,000, 192.0±9.5 for females and 83.9±6.3 for males. During the decade 2000–2009, the overall incidence rate of MS was 5.5±0.5, 7.4±0.8 for females and 3.5±0.6 for males. The onset-diagnosis delay, the female/male ratio and the mean age at onset did not significantly change compared to the prior period of observation. Conclusion: Our findings support the hypothesis of a real increased risk of developing MS in the province of Padova. Moreover, the actual prevalence of 1.4/1000 makes our region a high-risk geographical area for MS. The role played by exogenous factors in determining susceptibility to MS needs to be thoroughly investigated.