The National Academies

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?

About how much of its fish and seafood does the United States import?

  • Sorry, that’s incorrect.

    The United States imports more than 80 percent of its fish and seafood. About 20 percent of its fresh vegetables and 50 percent of its fresh fruits are imported. As wealthy nations demand such foods year-round, the increasing reliance on producers abroad means that food may be contaminated during harvesting, storage, processing, and transport—long before it reaches overseas markets.    

  • Sorry, that’s incorrect.

    The United States imports more than 80 percent of its fish and seafood. About 20 percent of its fresh vegetables and 50 percent of its fresh fruits are imported. As wealthy nations demand such foods year-round, the increasing reliance on producers abroad means that food may be contaminated during harvesting, storage, processing, and transport—long before it reaches overseas markets.    

  • Correct!

    The United States imports more than 80 percent of its fish and seafood. About 20 percent of its fresh vegetables and 50 percent of its fresh fruits are imported. As wealthy nations demand such foods year-round, the increasing reliance on producers abroad means that food may be contaminated during harvesting, storage, processing, and transport—long before it reaches overseas markets.    

Infectious Disease Defined

Tissue Culture

The process by which tissues are intentionally grown under controlled conditions.

View our full glossary

National Academies

Search the National Academies Press website by selecting one of these related terms.