Measles & Other Microbes

Federal health officials have reported that sixty-four cases of measles were reported during the first four months of 2008. That already exceeds the number of cases reported during all of 2006. Officials predict this number will continue to rise.

For years, measles affected more than three million Americans annually. It killed several hundred children and hospitalized thousands each year. In 1963, the measles vaccine became available in the U.S., and reported cases dropped quickly.

Today, the measles virus still kill about 242,000 children each year worldwide, and travelers from abroad can bring measles into the United States. Most Americans who become infected have never been vaccinated.

The measles virus is not the only microbe to cause human health concerns. Other pathogens include varieties of influenza, such as the "bird flu," which have spurred outbreaks of sickness that can sometimes lead to death. Bacteria can also spread infectious diseases, like tuberculosis. On the other hand, not all microbes are enemies.

During this week's lesson, you will discover the differences between a virus and bacterium. You will also learn how some microbes are actually good for our health. Finally, you will see how vaccines are made.

Probing the World of Microbes

Start your exploration at Microbeworld to find out how scientists determine whether a microbe is Virus or Bacterium.

Browse the Types of Microbes to review the six microbe groups: Archaea, Bacteria, Fungi, Protista, Viruses, and Microbial Mergers. Also read about Where They Live.

As you explore these pages, record the characteristics and preferred environment for each group and subgroup. Brainstorm familiar places where you would come across examples of each. In what kinds of environments would microbes not be found? In what ways do some bacteria live in mutually beneficial relationships with humans?

To get an idea of how scientists have been able to find and learn about microbes, review the Discovery Timeline and the Tools & Techniques section. In what specific ways do Microscopes, Culture Equipment, and Genetics Tools and Techniques aid scientists?

Now, research microbes more closely by visiting Cells Alive! Start in the Cell Biology section and watch the How Big is a…? animation. Increase the magnification and mouse over the names to identify each item.

In the Microbiology section, you will learn more about bacteria by examining a few examples. Read through the pages explaining Bacteriophage, Dividing Bacteria, Bacteria Motility, Penicillin, Helicobacter pylori, and Streptococcus. Make sure to watch the related animations and videos, where available.

With classmates, compare and contrast the nature of bacteria, viruses, and the other microbes.

Making Vaccines

Thanks to the collective efforts of many scientists over the years, vaccines have been created to halt a number of harmful microbes. So, how did they do that? To get an idea of how the process works, visit NOVA's Killer on Campus site. Open the Making Vaccines interactive.

Select each of the six pathogens, one at a time, to produce each vaccine. As you go through the steps for each procedure, diagram the steps in a flowchart and include the result of each step. When you have completed all six vaccines, discuss with classmates why there are different procedures for different pathogens.

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Newspaper Activities

Watch for news about pathogens in issues of Targetnewspaper. Pick one particular pathogen to research deeper. Is the pathogen a virus, bacteria, or other type of microbe? How does it spread? In what areas of the world has it been reported to exist now and in recent history? How much do scientists know about this pathogen? Develop a poster to explain the pathogen, its impacts, and what scientists are doing to combat its effects. What particular challenges do scientists face?