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The National Academies: What You Need To Know About Infectious Disease

What You Need To Know About Infectious Disease

How Infection Works

Types of Microbes

The microorganisms, or microbes, that can cause disease come in different forms. Viruses and bacteria are probably the most familiar because we hear so much about them. But fungi, protozoa, and helminths are also big players in the story of infectious disease. Learn more about each of these five main categories, as well as a recently discovered one: prions.

Viruses

Viruses

Viruses are unable to reproduce until they invade and commandeer living cells.

Influenza, measles, and the common cold are just some of the diseases caused by viruses. What is a virus and how is it different from other microbes?

More about viruses

Bacteria

Bacteria

Bacteria come in three shapes: spherical, rodlike, and curved.

Bacteria are single-celled organisms that have been around for billions of years. Discover their important characteristics.

More about bacteria

Other Microbes

Other Microbes

Bread mold and hookworm, both infectious agents, are neither bacteria nor viruses.

Viruses and bacteria may be the most recognizable of the microbes that can cause infectious disease. But there are several other varieties. Learn about them here.

More about other microbes

Explore Other Topics

What do you know about infectious disease?

True or False: Most infectious diseases are not impacted by changes in the environment.

  • Sorry, that’s incorrect.

    Most infectious diseases are impacted by changes in the environment. Malaria, dengue, and viral encephalitis infections, for example, are highly sensitive to environmental changes.

  • Correct!

    Most infectious diseases are impacted by changes in the environment. Malaria, dengue, and viral encephalitis infections, for example, are highly sensitive to environmental changes.

Infectious Disease Defined

Trachea

The main trunk of the network of tubes that carries air to and from the lungs, sometimes referred to as the “windpipe.”

View our full glossary

National Academies

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