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.

More about encountering microbes

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

Explore Other Topics

What do you know about infectious disease?

“Antibiotic resistance” refers to:

  • Sorry, that’s incorrect.

    “Antibiotic resistance” refers to the ability of bacteria to resist the effects of an antibiotic. Antibiotic resistance occurs when bacteria undergo a genetic change that reduces or eliminates the effectiveness of drugs or other agents designed to cure or prevent infection.

  • Sorry, that’s incorrect.

    “Antibiotic resistance” refers to the ability of bacteria to resist the effects of an antibiotic. Antibiotic resistance occurs when bacteria undergo a genetic change that reduces or eliminates the effectiveness of drugs or other agents designed to cure or prevent infection.

  • Correct!

    “Antibiotic resistance” refers to the ability of bacteria to resist the effects of an antibiotic. Antibiotic resistance occurs when bacteria undergo a genetic change that reduces or eliminates the effectiveness of drugs or other agents designed to cure or prevent infection.

Infectious Disease Defined

Antibodies

A class of drugs used to kill or inhibit the growth of disease-causing microorganisms. Typically antibiotics are used to treat infections caused by bacteria, but in some cases they are also used against other microorganisms, such as fungi and protozoa.

View our full glossary

National Academies

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