Identification of Arboviruses and Certain Rodent-Borne Viruses: Reevaluation of the Paradigm

Reevaluation of the ParadigmDiagnostic and epidemiologic virology laboratories have in large part traded conventional techniques of virus detection and identification for more rapid, novel, and sensitive molecular methods.By doing so, useful phenotypic characteristics are not being determined.We feel that the impact of this shift in emphasis has impaired studies of the biology of viruses.This position paper is a plea to the scientific and administrative communities to reconsider the importance of such information.We also suggest a revised paradigm for virus isolation and characterization and provide a rationale for accumulating biologic (phenotypic) information. Historical BackgroundUntil about 10 years ago, arthropod-borne viruses (arboviruses) were isolated and then identified by methods now referred to as "classical."That is, clinical or fieldcollected samples were processed by methods originally established by yellow fever researchers at the Rockefeller Foundation (1-3).As these procedures were shared and adopted by essentially all laboratories conducting arbovirus surveillance and research, they became the standard for arbovirus laboratories worldwide.These techniques were developed to facilitate specific identification of viruses isolated from hematophagous arthropods, vertebrate animals, and human clinical samples.The general scheme included a) isolation of the virus; b) production of a virus seed or stock; c) production of a sucrose-acetone extracted antigen (often inactivated so that it could be used safely for serodiagnostic procedures); d) preparation of an antibody (usually hyperimmune mouse ascitic fluids); e) registration of the virus; and f) deposition of the virus as a voucher specimen in a reference collection (3,4).The accumulation of such reagents by arbovirus laboratories allowed the establishment of reference centers that, with the support and encouragement of the World Health Organization (5,6) and various national governments, distribute useful reagents to regional and local laboratories.Local laboratories, in turn, were then able to conduct serodiagnostic tests for antibody to newly recognized arboviruses, using standardized reagents for virus identification procedures.As an intentional by-product, a network of collaborating centers was established and an international spirit of cooperation and camaraderie evolved, as exemplified by the American Committee on Arthropod-Borne Viruses (ACAV) and its various subcommittees that take responsibility for collating a catalog of the recognized arthropod-borne and rodentassociated viruses (7), evaluating their safety, storing voucher specimens, and determining their antigenic relationships.The resulting catalog, entitled The International Catalogue of Arboviruses and Certain Other Viruses of Vertebrates, has long been the "bible" of arbovirologists.However, with the availability of newer molecular techniques and the current emphasis on genomics, many viruses now are detected by molecular means only.Consequently, few newly discovered viruses are now being registered in the arbovirus catalog, although hundreds of genomic sequences of arboviruses, hantaviruses,