ABSENCE OF HTLV-1 RELATED SEQUENCES IN MS FROM HIGH PREVALENCE AREAS IN WESTERN NORWAY

In Western Norway, long-term follow up epidemiological studies have re vealed significant increases in the incidence and prevalence rates of multiple sclerosis (MS) in stable populations, indicating the impact o f exogenous factors. In this study 183 MS patients and 102 controls fr om high prevalence areas in Western Norway were investigated for human T-lymphotropic virus type I (HTLV-1) related sequences by polymerase chain reaction. Using primers targeting the gag, pol and env genes in the HTLV-1 provirus genome, no amplification products were detected in the 183 MS patients or 102 controls. The results.strongly suggest tha t neither HTLV-1 nor a closely related retrovirus participate in the a etiology of MS.