Study questions for Topic 9

1. What are the four main drivers of virus evolution?
2. What is the error threshold? Is this concept an issue relevant to all viruses? What is a quasispecies and why is it so important in virology?
3. Explain these two concepts: “survival of the fittest” versus “survival of the survivors”. Is reassortment the only method of genetic exchange among viruses?
4. There is an epidemic of rats in NYC. The Mayor asks you to release a virus into the rat population to control the animals. Is this a good idea? Why or why not?
5. Did dinosaurs have herpes? How would we know?
6. All new viruses come from existing ones. Explain. Why can’t entirely ‘new’ viruses emerge?

Emerging infections

1. In the contemporary era, what are the factors that lead to the emergence of new viral infections emerge?
2. What are: stable, evolving, dead­‐end, and resistant host­‐virus relationships? What do they have to do with emergence?
3. Explain what factors lead to Hendra and nipah virus emergence.
4. What was the origin of SARS? Why did it spread globally? How was it contained?
5. Discuss the conditions that lead to the emergence of the Sin Nombre virus in humans in 1992‐93. How did canine parvovirus emerge in 1978? It really was not around before that, was it?