Prevalence of Multiple Sclerosis in the Sanitary District of Calatayud, Northern Spain: Is Spain a Zone of High Risk for this Disease?

Abstract

We undertook an epidemiologic study to ascertain the prevalence of multiple sclerosis (MS) in the Sanitary District of Calatayud, in the north-east of Spain. Methods: The study was performed from October 1990 to July 1996. The total number of residents in the area was 58,591. An extensive search was carried out to identify all cases of known or suspected MS through general practitioners and specialists, sanitary authorities in the area, the reference hospital, the Spanish Multiple Sclerosis Society, the newspaper and radio. Results: April 1, 1995 was chosen as prevalence day. The crude prevalence rate for the area was 58 per 100,000 (95% CI: 39–78). The approximate annual incidence rate was 2.6/100,000 (1980–1989). Conclusions: This study and others conducted recently in Spain show that MS is more prevalent than was previously thought and afflicts at least 53–65 per 100,000 population.

Long‐term epidemiology of multiple sclerosis in the N orthern S eville D istrict

“…Likewise, the annual incidence rate of the current study over a 20‐year period was 4.6 per 100,000, a figure much higher than that reported in previous epidemiologic studies in Spain (incidence rates of between 2.2 and 3.8 per 100,000 per year) 19, 22, 23, 25. As the genetic background of the population of Northern Seville District of Spain is not very different from other areas of Spain and the rest of South Europe, this was unexpected.…”

“…report a much higher prevalence of MS than in previous epidemiologic studies conducted in the 1990s in various regions of Spain (32–65 per 100,000 population), including an earlier study in southern Spain by Fernandez et al. 19, 20, 21, 22, 23, 24, 25. The higher prevalence compared with earlier studies is probably related to numerous factors, including higher survival in MS and better diagnostic accuracy 26.…”

“…As the genetic background of the population of Northern Seville District of Spain is not very different from other areas of Spain and the rest of South Europe, this was unexpected. However, these studies analysed incidence over much shorter time frames, the longest being a 10‐year period in a study in northern Spain 23.…”

Study of HLA as a Predisposing Factor and Its Possible Influence on the Outcome of Multiple Sclerosis in the Sanitary District of Calatayud, Northern Spain

“…The most significant differences were observed for the HLA A19 (odds ratio, OR: 2.29, p = 0.04) and two of its splits: A31(19) (OR: 5.22, p = 0.03) and A33 (19) (OR: undefined, p = 0.03). None of the HLA-A antigens were found to be more frequent in the controls than in the patients.…”

“…We also obtained radio and press collaboration. Thirty-four patients were identified with clinically definite MS in this area [19]. Determination of histocompatibility antigens of class I (A, B, C) and class II (DR and DQ) was possible in 31 MS patients, 21 women and 10 men.…”