Migration and multiple sclerosis: the French West Indies experience.
The French West Indies (FWI), i.e., the islands of Martinique and Guadeloupe, have recently experienced the emergence of multiple sclerosis (MS). This epidemiological upheaval followed a return migration of the FWI population that had previously migrated to continental France. The prevalence MS was 14.8/10(5) (95% CI: 11.9-17.7) on Dec. 31, 1999 and its mean annual incidence was 1.4/10(5) (95% CI: 1.0-1.8) for the period July 1997 to June 2002. The prevalence of MS in Martinique, that received more return migration, is higher than that of Guadeloupe (21.0/10(5) vs. 8.5/10(5)). This emergence of MS has been accompanied also by an inversion of its clinical spectrum, with recurrent neuromyelitis optica accounting for only 17.8% of cases. The standardized ratio of the incidence of MS among migrants is 1.71 (95% CI: 1.19-2.38; P<0.01) and if migration to continental France occurred before the age of 15 it is 4.05 (95% CI: 2.17-6.83; P<0.0001). According to recent data, a drastic reduction in exposure to sunlight and to intestinal parasites during childhood, found preferentially among migrants, are possible environmental factors responsible for this emergence.
Cabre
Philippe
P
Service de Neurologie, CHU Fort de France, Hôpital Pierre Zobda Quitman, BP 97261, Fort de France, Martinique, France. pcabre_fr@yahoo.fr
D015984:Causality; D015897:Comorbidity; D004641:Emigration and Immigration; D004777:Environment; D005602:France / Q000453:epidemiology / Q000208:ethnology; D006801:Humans; D015994:Incidence; D007411:Intestinal Diseases, Parasitic / Q000453:epidemiology / Q000276:immunology; D009103:Multiple Sclerosis / Q000453:epidemiology* / Q000208:ethnology / Q000276:immunology; D013472:Sunlight; D014900:West Indies / Q000453:epidemiology / Q000208:ethnology