New Virus Discovery in the 21st Century

Abstract

The development of new technologies has propelled virus discovery efforts forward at an unprecedented pace. As this area of research has become increasingly active, a review of virus discovery efforts over the last ~10 years is warranted. This chapter describes the evolution of sequence-independent PCR methods, panviral microarrays, and mass sequencing in the discovery of novel viruses. It also highlights the viruses discovered by these methods, and the importance and novelties of some of these viruses. Sequence-independent PCR strategies and new technologies such as microarrays and mass sequencing, while not without their own limitations, circumvent many of the limitations associated with traditional virus discovery methods and consequently have revolutionized the process of virus discovery. The discovery in 2001 of a novel human pneumovirus, called human metapneumovirus (HMPV), relied upon a sequence-independent PCR approach in conjunction with viral culture to identify a previously unknown virus. The first application of virus discovery based on cDNA-amplified fragment length polymorphism (VIDISCA) to virus discovery resulted in the identification of HCoV-NL63. DNA microarrays first emerged in the mid-1990s as powerful tools to measure gene expression or genomic content changes in various organisms. Dideoxy sequencing or Sanger sequencing, first described in 1977, has been the dominant DNA sequencing technology used during the last ~30 years. With the advent of new technologies, a shift has occurred such that in many instances, the rate-limiting step is no longer discovery but understanding the biological relevance and impact of newly discovered viruses.