Virus Notes

VirusesWhat We Will Learn

  • Definition of Viruses

  • Structural characteristics

  • Classification

  • Replication and Life Cycle

  • Genetics and Viral Evolution

  • Pathogenesis of Viral Infections

  • Virological diagnostics

  • Antiviral drugs

Viruses and Their Impact

  • Viruses cause over 2,000 deaths per year, highlighting their significant impact on public health.

  • They are obligate intracellular parasites, relying on host cells for survival and propagation.

  • Viruses can infect all types of life forms, from animals and plants to microorganisms, including bacteria and archaea, showcasing their broad host range.

  • Examples include:

    • FLU virus

    • HCV

    • HIV-1

A Little Bit of History

  • 1884 LOUIS PASTEUR: He was the first to propose the term 'virus,' marking an early conceptualization of these infectious agents.

  • 1892 DMITRI IVANOVSKY: Discovered that infected plant extract could still transmit disease even after being filtered, leading to the realization that the infectious agent was much smaller than bacteria.

  • 1898 MARTINUS BEIJERINCK: Called the filtered infectious substance a 'virus,' solidifying the term in scientific vocabulary.

  • 1935 WENDELL STANLEY: Showed that the tobacco mosaic virus (TMV) is largely composed of protein.

    • Was able to crystallize it, representing the first time anyone had purified and crystallized a virus.

    • It could remain infectious even after crystallization, an intriguing property that challenged early understanding.