Concept Questions - Chapter 25
Take some time to write answers to these questions.
If you can answer them, you have a good grasp of the material!

1. Describe the structure and functions of the hemagglutinin and neuraminidase spikes in influenza virus.
What is unusual about the genome of influenza virus?

Use drawings and words to explain the concepts of antigenic drift and antigenic shift, and explain their impact on the epidemiology of this disease.
How does the CDC anticipate which flu strains will predominate each year?
How do the names for the types of flu originate?

2. Explain the course of infection and disease in influenza.
What are the complications?
How is the vaccine prepared, and for which groups is it indicated?

3. Give examples of Bunyaviruses and arenaviruses,
Briefly describe the nature of the diseases they cause.

Describe their modes of transmission.

4. Describe the steps in the production of multinucleate giant cells during a viral infection.

Which viruses have this effect, and what impact does cell fusion have on the spread of infection?

5. Describe the progress of measles symptoms.
What is the cause of death in measles, and what are the most severe complications of measles infections?
Describe methods of treatment and prevention for measles.

6. Describe the epidemiologic cycle in rabies.
Which animals in the United States are most frequently involved as carriers?
Describe the route of infection and the viruses’ pathologic effects.
Why is rabies so uniformly fatal?
Describe the indications for pre- and postexposure rabies treatment.
What is given in postexposure treatment that is not given in preexposure treatment of rabies?
What makes the latest vaccine less traumatic than earlier ones?

7. What is a teratogenic virus?
Which RNA viruses have this potential?
In what ways is rubella different from red measles?
What is the protocol to prevent congenital rubella?

8. What are the principal carrier arthropods for arboviruses?

How is the cycle of the virus maintained in the wild?

Describe the symptoms of the encephalitis type of infection (WEE, EEE) and the hemorrhagic fevers (yellow fever).

9. What are retroviruses, and how are they different from other viruses?
Give examples of the three principal human retroviruses and the diseases they cause.
Give a comprehensive definition of AIDS, and define categories of HIV disease as characterized by the CDC.

10. Briefly explain the activities most likely to spread AIDS and what factors increase the relative risk among certain populations.
Explain why bone marrow transplants are a transmission concern.
Discuss some ways that HIV has not been documented to spread.

11. Discuss whether AIDS is an all-or-none disease, or a series of gradual pathologic changes.

Differentiate between HIV infection, HIV disease, and AIDS.
What are the primary target tissues and changes?
Explain why only certain T cells are targeted by HIV and what it does to them.
How is the brain affected by infection?
What major factors cause the long latency period in AIDS?
What does it mean to be a non-progressor?

12. Describe the changes over time in virus antigen levels, antibody levels, and CD4 T cells in the blood of an HIV-infected individual.

Relate these changes to the progress of the disease, the infectiousness of the person, and the effectiveness of the
immune response to the virus.

13. List the major opportunistic bacterial, fungal, protozoan, and viral diseases used to define AIDS.
Describe four other secondary diseases or conditions that accompany AIDS.
Explain which effects HIV has that create vulnerability to these particular pathogens and the other conditions.

14. If a person is seropositive for HIV, does this mean that the patient has AIDS?

What is the most sensible interpretation of a seronegative result for a
monogamous person who has not had a blood transfusion or taken IV drugs?

What is a logical interpretation of a seronegativity in a person who has
participated in high-risk behavior?

What is meant by the "window" regarding antibody presence in the blood?

15. How do AZT and other nucleotide analogs control the AIDS virus? How do protease inhibitors work?
Are there any actual cures for AIDS?
What is the rationale behind the new "drug cocktail" treatment?
Explain several strategies for vaccine development; include in your answer the primary drawbacks to development of an effective vaccine.

16. Describe the epidemiology and progress of polio infection and disease.
What causes the paralysis and deformity?
Compare and contrast the two types of vaccines.
What characteristics of enteric viruses cause them to be readily transmissible?

17. Describe some common ways that hepatitis A is spread.
What are its primary effects on the body?
How is it different from hepatitis B?

18. What is the common cold, and which groups of viruses can be involved in its transmission?
Why is it so difficult to control?

Discuss the similarities in the
symptoms of influenza, parainfluenza, mumps, measles, rubella, RSV, and
rhinoviruses.

19. For which of the RNA viruses are vaccines available?
Which viruses will probably never have a vaccine developed for them and why?
For which of the RNA viruses are there specific drug treatments?
Provide the formal genus name for each of the English vernacular names of viruses listed in multiple-choice matching questions 16 and 17.

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