A control and case study of multiple sclerosis in the Alicante and Villajoyosa areas

INTRODUCTION: Three studies have been carried out in the area of Alcoy (Spain) which show an association between contact with dogs and multiple sclerosis. We present a control and case study conducted in a different geographical area, the area of Alicante. AIMS. To examine environmental factors linked with multiple sclerosis in the health care district of Alicante, and to compare findings with those from the health care district of Alcoy. PATIENTS AND METHODS: A study of cases and controls was conducted with 47 patients, each of which was paired with four controls according to gender, age and place of residence. All the cases fulfilled criteria of defined multiple sclerosis. The controls were obtained from the Emergency and Casualty Services at different hospitals in the area. Each of the environmental factors studied was stratified by genders. RESULTS: A total of 47 patients and 188 controls were analysed. A statistically significant association was found between the disease and smoking, a low educational level, a social level 2 on the classification developed by Koch Henriksen, having had measles before the age of 15 and contact with dogs. The fact of being the third, or later, child in a family and a family history of cephalea were more frequent among controls than among cases. CONCLUSIONS: Multiple sclerosis in the Alicante area is related with contact with dogs, smoking, a low educational level, a high social level and measles before the age of 15. Since an association between contact with dogs and multiple sclerosis has been shown repeatedly in other previous studies conducted in the town of Alcoy, we are now in a position to state that this factor is indeed linked with the appearance of multiple sclerosis.