Since the subject of arenaviruses was visited by "Current " "Topics in Microbiology and Immunology" 14 years ago, enormous advances have been made in this area. The receptor for several arenaviruses, alpha-dystroglycan, was identified, the replication strategy of these viruses was decoded, and application of a reverse genetics system for studying viral gene function and viral biology is well underway.
In addition to reviewing these advances, Volume I includes discussion of arenaviral molecular phylogeny, reservoirs in rodents and clinical diseases caused by both new world and old world arenaviruses.

Viruses are studied either because they cause significant human, animal or plant disease or because they are useful materials for probing basic phenomena in biology, chemistry, genetics and/or molecular biology. Arenaviruses are unusually interesting in that they occupy both categories. Arenaviruses cause several human diseases known primarily as the hemorrhagic fevers occurring in South and Latin America (Bolivia: Machupo, Argentine, Junin virus, and Brazil: Sabia virus) and in Africa (Lassa fever virus). Because such viruses produce profound disabilities and often kill the persons they infect, they are a source of health concern and economic hardship in the countries where they are prevalent. Further, they provide new problems for healthcare persons owing to the narrowing of the world as visitors from many countries travel increasingly to and from endemic areas and may incubate the infectious agent taking it from an endemic area into an area where the virus is not expected. Such cases are now being re corded with increasing frequency. In addition to these hemor rhagic fever viruses, the arenavirus lymphocytic choriomeningitis virus (LCMV) can infect humans worldwide, although the illness is most often less disabling and severe than those elicited by the other arenaviruses. Yet, LCMV is of greater concern to non arenavirologists and experimentalists using tissue culture or ani mals, etc. , because normal-appearing cultured cells or tissues from animals used for research may be persistently infected with LCMV without manifesting clinical disease or cytopathology and may transmit that infection to laboratory workers.

The current proliferation of scientific information makes it difficult for even the most diligent reader to keep up with the latest developments in his/her own field, let alone other areas of interest. Review articles are one solution, but they too have become so voluminous and detailed that they often defeat the purpose for which they were intended. We have attempted to ease this problem by using a different format. In this volume on Concepts in Viral Pathogenesis, we have assembled a series of mini-reviews/editorials, 1,000 to 2,000 words in length. Each is a pithy distil lation of the state-of-the-art with emphasis on current thinking and unifying concepts rather than a compendium of the literature. The 53 articles, all written by active workers in their respective fields, are organized systemati cally so that the book will provide busy investigators, teachers and students of up-to-date information in a very brief and easily read a conceptual core able form. In addition, the authors have attempted to identify unresolved problems and point to future directions."