The first theme of next week’s class (Week 2) will be Chapter 2, Concepts of Infectious Disease. I will briefly go through the chapter to make sure that you understand it, and then we will have a discussion.

Since the chapter in the textbook is so full of important concepts, it would be difficult to narrow it down to a single topic for discussion. So I have posted this introduction and 3 separate subtopics. You can choose which one you want to write about. Each student should choose one of these subtopics for your major post. You should write well thought out primary comments on at least one of the points below (150-200 words).

BE SURE TO INCLUDE YOUR NAME AND SUBTOPIC IN THE HEADER FOR YOUR PAPER.

We will discuss each of the subtopics that were chosen by the students. Each of you should take an active role in presenting your topic to the other students. Explain the concept in your own words, or develop it further using a relevant example. As other students present their perspective on the same topic, hopefully an active discussion will take hold. I will jump in only as needed. This format will allow you to develop one subtopic in an active sense, but learn about the others by being drawn into them through other people’s discussions.

Choose your subtopic:

Subtopic 1: Factors that affect the spread of epidemics

Question: Explain how the interaction between these factors are relevant to the transmission of AIDS. For example, which of these factors are most critical to the transmission of HIV. Which aren’t.

1. Total number of hosts

2. Host’s birth rate

3. Rate at which new susceptible hosts migrate into population

4. Number of susceptible uninfected hosts

5. Rate at which disease can be transmitted from infected to uninfected hosts

6. Death rate of infected hosts

7. The number of infected hosts who survive and become immune or resistant to further infection

Subtopic 2: Acute versus Chronic Infections

Question: Compare the definitions of Acute Infections and Chronic Infections below. Based on what you know about HIV/AIDS at this point, which description most closely matches AIDS? Explain your answer, using evidence from the book to support your position.

What is an acute infection?

1. Produces symptoms and makes a person infectious soon after infection.

2. The infected person may:                                                                                                                        transmit the disease

die from the infection

recover and develop immunity

3. the acute microorganism

STRIKES QUICKLY

infects entire group (small group)

dies out

What is a chronic infection?

Person may never show symptoms

Person continues to carry infectious agent at a low level

Does NOT mount an effective immune response

Subtopic 3: Controlling infectious disease

Question: Explain what herd immunity is and how it works. Use an example from either the book or the internet to explain your position.

Herd immunity = when all, or nearly all susceptibles are immunized, no new infection can occur. Agent can be eradicated from the population.