Keeping Track of Viruses

This chapter introduces basic concepts of virology and exemplifies the usage of current technology for identifying and tracking viral pathogens. Virus structure, lifestyle, replication strategies, classication, the varied modes of transmission, infection, and disease manifestations are focussed upon in the chapter. Viruses are extremely simple “life” forms without metabolic capacity, organelles, translational machinery, or autonomous replicative potential; the essential elements of a virus are consequently minimal. A virus enters the host through any opportunistic opening of the body—; such as minute breaks in the skin barrier or mucosal linings of the eye, nose, etc. Antibodies produced during an infection often have the ability to bind the virus and reduce infectivity. An immediate question to solve during a virus outbreak is the mechanism by which the virus spreads. Viruses frequently infect animal or insect vectors that serve to pass the virus to humans. By identifying the virus through sequence analysis, a hypothetical reservoir can be predicted by the placement of the sequence on the phylogenetic tree‥ The varied modes of transmission, infection, and disease manifestations as they relate to the different diagnostic methods for virus identification are highlighted. Examples of naturally emerging viruses; such as Sin Nombre, Nipah, West Nile conclude the chapter. New technologies that allow the creation of manmade or “engineered” viruses, new frontiers in viral diagnostics, and a few thoughts on the future of virology are also presented. The global eradication of smallpox ranks as one of humankind's greatest accomplishments yet many viral challenges remain. HIV, hepatitis B and C, influenza, dengue, rotavirus, and many other viral diseases continue to affect tens of millions.