Prevalence and incidence of Multiple Sclerosis in Campobasso (Molise region chieftown, southern Italy). 
Multiple Sclerosis in southern Italy was not epidemiologically studied until 2006 in Salerno (Campania region), with data based on the registry of district MS centers established since 1996 by Italian Ministry of Health.  This paper reports data about Molise region by the same metodology as Campanian study.  The registry of MS center was searched for the city of Campobasso, chief town of Molise region.  Population screened: 51,633 units.  ISTAT 2005 data were used for comparison and age standardization.  Prevalence day: September 30, 2009; incidence was calculated by cumulative rates 1996-2000 and 2001-2005.  47 patients were collected, 17 males, 30 females, age 44.10 (9-74, SD 14.38); female/male ratio=1.76/1; age onset 34.61 (4-61, SD 12.40); mean disease duration 9.48 years (0-24; SD 4.28).  Males prevalence: 68.62/100,000; females: 111.68/100,000.  Total prevalence: 91.02/100,000; standardized: 90.91/100,000.  Incidence rates: 1996-2000: 10.84/100,000; 2001-2005: 4.26/100,000.  Prevalence is coherent with previous Campanian data, and with last epidemiologic papers on middle Italy, confirming also the validity of MS district centers registries.  A possible underestimation of data, for some patients could still migrate to northern centers, could contribute to the differences in incidence.  Nevertheless, prevalence data confirm southern Italy as high risk area for MS, and stands against a latitude gradient in this country.