Papel de las enfermedades infecciosas en el desarrollo de la esclerosis múltiple: evidencia científica

INTRODUCTION: Multiple sclerosis (MS) is the most common inflammatory disease of the central nervous system (CNS) and the leading cause of neurological disability in young adults. Environmental and infectious factors had been strongly associated and involved in the increased occurrence of MS, to more than twice, in the last 10 years. In this review, we describe the main findings on the relationship between viral and bacterial infections and the onset and progression of MS. METHODS: The research involved a systematic review of scientific literature regarding infection and MS. Our search was performed using and consulting specialized websites like PubMed, Medline and Cochrane. The keywords (MeSH terms) employed for the digital search were: “virus, bacteria, autoimmune disease of the nervous system, and multiple sclerosis.” Articles published in English indexed journals during the past 15 years were used for the study. RESULTS: Epidemiological studies suggest that MS has an infectious etiologic component causing an inflammatory process that may contribute to the initiation and/or exacerbation of the disease. Particularly, viral infections and demyelination events in the CNS may be due to the penetration of viruses such as the Epstein-Barr virus (EBV) through the bloodstream to the CNS, specifically. On the other hand, chronic bacterial infections may cause demyelination processes that trigger or increase the complications of the disease in MS. CONCLUSIONS: This study shows the multiple factors involved in the occurrence of MS. More epidemiological studies are necessary to support the relationship and involvement of viral and bacterial infections in the onset, development and severity of the disease.