Introduction: The epidemiological studies done in Spain in recent years show higher figures for the prevalence of multiple sclerosis than before. Spain is therefore now in the area with a high risk of contracting the disease.
Objective: We have made a new study to confirm the current prevalence of the disorder in the Alcoi Health District.
Patients and methods: Between 1 March 1986 and the prevalence day, 31 December 1997 we recorded the patients with definite or probable multiple sclerosis, as defined on Poser's criteria, after intensive fieldwork and reevaluation of all possible patients by a neurologist from the Neurology Unit. On the prevalence day there were 130,786 inhabitants in the district.
Results: On the prevalence day we found 54 patients with definite multiple sclerosis and no patient with probable multiple sclerosis. The rate of prevalence was 41.28 cases per 100,000 inhabitants (95% CI: 31-53.6). During the study we counted an incidence of 45 cases with an average rate of 2.82 cases per 100,000 inhabitants per year. We also describe the clinical characteristics of the patients.
Conclusions: The rate of prevalence found is much higher than that described for the district in studies using similar methodology. This increase, together with the discrepancy between the incidence found and the prevalence, makes us consider that possibly the prevalence has increased in recent years.