VIRAL-INFECTIONS TRIGGER MULTIPLE-SCLEROSIS RELAPSES - A PROSPECTIVE SEROEPIDEMIOLOGICAL STUDY

A neurological surveillance was combined with prospective recording of upper respiratory and gastrointestinal infections and serological dia gnosis of five common viral infections in 60 benign multiple sclerosis patients, with a mean follow-up of 31 months. During 4-week at risk ( AR) periods encompassing common infections, a significant excess of MS relapses was found in the AR period, with a relative risk of 1.3. A s easonal variation of the MS relapse rate was found with a minimum in s ummer. There was a significant correlation between the number of AR re lapses and the number of common infections per month explaining the pe riannual distribution of relapses. The non-AR relapses showed no seaso nal variation. There was a significant correlation between adenovirus CF titre rises associated with upper respiratory infections and the oc currence of a major MS relapse in the AR period (n = 7), while influen za infections were not followed by a major MS relapse (n = 6). Linear homologies have been demonstrated between adenovirus and basic myelin protein. The epidemiological approach is essential to our understandin g of systemic antigens triggering multiple sclerosis activity.