Lecture 1.2 - Intro to Virology - Microimm 2500

Importance of Virology

Introduction to Pandemics

• Current global pandemic situation (SARS-CoV-2) with extensive implications for health and society.

• Emergence of a pneumonia-causing virus initially reported in Wuhan on December 30, 2019.

• Importance of monitoring infectious diseases through programs like Pro-MED.

Case Study: Measles Outbreak

• Example of a measles outbreak traced back to an unvaccinated individual who traveled from Indiana to Eastern Europe.

• Details on the outbreak include patient histories and consequences of vaccine hesitancy.

• Significant costs incurred in containing the outbreak estimated at $168,000.

Global Cases and Incidents

Data Overview

• Cumulative COVID-19 cases and deaths.

• Importance of vaccination in mitigating outbreaks and understanding viruses in society.

• Historical data showing vaccination impact on diseases such as measles.

Types of Viruses in Society

Examples of Viral Infections

• Example Case: 17-year-old unvaccinated male with measles leading to numerous confirmed cases due to a single gathering.

• Predictions about infection rates illustrate the high contagion level associated with measles.

Virological Defense Mechanisms

Viral Interactions with Hosts

• Exploration of how many viruses do not cause illness in humans and the innate immune defenses that exist.

• Discussion of the impact of viral-host interactions on medical knowledge.

Perspectives on Viruses

Viruses are not inherently harmful

• Positives and benefits associated with some viral relationships, e.g., polydnaviruses aiding wasps in egg-laying processes.

• Noteworthy that viruses can be critical to ecological interactions, beneficial even.

Major Concepts in Virology

Framework for Understanding Viral Functionality

1. Viral Genomes:

   • Must be packaged in particles for transmission.

   • Host reliance for replication and survival.

   • Establishing long-term relationships within hosts for continued existence.

2. Obligate Molecular Parasites:

   • Viruses require a host cell for replication and function.

   • Utilization of host machinery for viral protein synthesis, demonstrating their non-independent nature.

Historical Context of Virology

Evolution and Discovery

• Viruses have existed for millions of years, with early documentation by Ancient Greeks and Romans.

• Tobacco mosaic virus identified as the first viral agent in plant pathology, leading to the understanding of viruses' biological nature.

• The discovery of the first animal virus (foot-and-mouth disease) highlights the importance of filterability in identifying viruses.

Techniques for Observing Viruses

• The role of electron microscopy in virology, showcasing the intricate structures of viruses.

• Mimiviruses as an exception, visible under light microscopy, emphasizing the advance of imaging technology in virus research.

Summary of Key Takeaways

• Definition: A virus is a small, infectious, obligate intracellular parasite that requires a host cell for replication and survival.

• Understanding viruses involves integrating knowledge across biology, immunology, and other scientific disciplines, promoting a holistic view of viral impact on life.