The Fundamentals of Human Virology

Viruses are molecular pathogens that cause human diseases. A conventional virus is made up of 2 or 3 major components. A nucleic acid genome, which can be Deoxyribonucleic Acid (DNA) or Ribonucleic Acid (RNA), single or double-stranded, contiguous or segmented, contains all the genetic information and encodes all the virus-specific macromolecules of the pathogen. The molecular and pathogenic aspects of their biology are grouped in terms of their genomic organization. Molecular characterization of these pathogens provides an understanding of mechanisms of pathogenesis, rational drug design, molecular signatures that can be used to trace outbreaks of viral disease… An overview of the six families of DNA and 15 families of RNA viruses, based on their molecular properties and life cycles is presented. The utility and issues surrounding the use of molecular forensics and epidemiology to the world of virology are exemplified, for instance, because of rapid sequencing techniques detailed fingerprints of viruses provide important clues about their source. Like other microbial species, the analysis of viral genomic segments can provide important clues as to the relatedness and origins of infections. Given their small size and high rate of evolution, several considerations should be kept in mind when applying comparative molecular forensic analyses to viruses. The tracking of HIV infections exemplifies the successful application of molecular forensics to identify the source of a viral infection. The goal of this chapter is to provide a background in the fundamentals of human virology and provide an overview of the utility and issues surrounding the use of molecular forensics and epidemiology to the world of virology.