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

Microbes occupy all of our body surfaces, including the skin, gut, and mucous membranes. Most don’t do us any harm—in fact, many help us survive. But there are certain bacteria, viruses, and other microbial life forms that can cause illness or even death. Here we learn the basics about microbes and the fascinating relationship we have with them.

Microbes & Humans

Microbes & Humans

A human body contains at least 10 times more bacterial cells than human ones.

Microbes and humans have evolved a complex relationship over thousands of years. Find out just how interconnected we are.

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Types of Microbes

Types of Microbes

There are five major categories of infectious agents. 

Viruses, bacteria, and fungi—oh my! Learn about the different microorganisms that are the source of infectious disease in people.

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Encountering Microbes

Encountering Microbes

Microbes may be the earliest life forms on Earth.

People and microbes have always shared this planet. But changes in the way we live are affecting how and where we encounter microbes. Discover the impact of our modern way of life.

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How Pathogens Make Us Sick

How Pathogens Make Us Sick

Infection does not necessarily lead to disease.

Pathogens (microbes capable of causing disease) call our immune systems into action. Find out more about how the body responds to these tiny invaders.

More about how pathogens make us sick

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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

Germ Theory

A theory in medicine stating that microorganisms are the causative agents of infectious, contagious diseases.

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