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

The National Academies

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 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 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

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

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Infectious Disease Videos

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What You Need to Know About Infectious Disease

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Disease Watchlist

What do you know about infectious disease?

True or False: Major pharmaceutical companies have great interest in dedicating resources to the antibiotics market because these short-course drugs are more profitable than drugs that treat chronic conditions and lifestyle ailments, such as high blood pressure or high cholesterol.

  • Sorry, that’s incorrect.

    Drugs that treat chronic conditions and lifestyle ailments are more profitable. Modern medicine needs new kinds of antibiotics to treat drug-resistant infections, but antibiotic research and development are expensive, risky, and time-consuming.

  • Correct!

    Drugs that treat chronic conditions and lifestyle ailments are more profitable. Modern medicine needs new kinds of antibiotics to treat drug-resistant infections, but antibiotic research and development are expensive, risky, and time-consuming.

Infectious Disease Defined

Bacteria

A large group of unicellular microorganisms that lack a cell nucleus. Some bacteria are pathogenic and harmful to humans, some have no effect at all on humans, and some are beneficial.

View our full glossary

National Academies Press

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