Chapter 23 - New Viruses and Diseases of the Human Central Nervous System

Abstract

This chapter describes the discovery and initial characterization of two novel viruses, multiple sclerosis-associated retrovirus (MSRV) and human Borna disease virus (BDV), which are tentatively associated with multiple sclerosis and with affective disorders and schizophrenia, respectively. Although many of the findings discussed below are intriguing and highly suggestive, it should be borne in mind that research in both these fields is still at an early stage, and that further work is required before aetiological links can be firmly established. Even though BDV may infect humans with associated clinical consequences, which are similar to those following animal infection, there are still unanswered questions. Reservoirs of BDV and the routes of transmission to humans are unknown. In addition, although BDV infection is demonstrated in neuropsychiatric patients, clear links with distinct disease entities have not yet emerged. To address these issues, multicentre studies are underway using standardized methodologies. The evidence linking BDV to human affective disorders is still speculative. Many of the findings have not been confirmed by independent research groups. It has also been claimed that some results achieved using RT-PCR may be due to laboratory contamination.