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

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

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.

More about microbes & humans

Types of Microbes

There are five major categories of infectious agents. 

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

More about types of 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

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

Infectious Disease Videos

Video thumbnail

7:20

What You Need to Know About Infectious Disease

View YouTube Channel

Disease Watchlist

What do you know about infectious disease?

Which are examples of ways that pathogens (disease-causing microbes) can spread?

  • Sorry, that’s incorrect.

    All are examples of ways that pathogens can spread. Coughing is an example of airborne droplet transmission; eating undercooked pork is an example of common vehicle transmission; a flea bite is an example of vector transmission; and breathing contaminated dust particles is an example of airborne transmission.

  • Sorry, that’s incorrect.

    All are examples of ways that pathogens can spread. Coughing is an example of airborne droplet transmission; eating undercooked pork is an example of common vehicle transmission; a flea bite is an example of vector transmission; and breathing contaminated dust particles is an example of airborne transmission.

  • Sorry, that’s incorrect.

    All are examples of ways that pathogens can spread. Coughing is an example of airborne droplet transmission; eating undercooked pork is an example of common vehicle transmission; a flea bite is an example of vector transmission; and breathing contaminated dust particles is an example of airborne transmission.

  • Sorry, that’s incorrect.

    All are examples of ways that pathogens can spread. Coughing is an example of airborne droplet transmission; eating undercooked pork is an example of common vehicle transmission; a flea bite is an example of vector transmission; and breathing contaminated dust particles is an example of airborne transmission.

  • Correct!

    All are examples of ways that pathogens can spread. Coughing is an example of airborne droplet transmission; eating undercooked pork is an example of common vehicle transmission; a flea bite is an example of vector transmission; and breathing contaminated dust particles is an example of airborne transmission.

Infectious Disease Defined

Schizophrenia

A serious mental illness characterized by the presence of hallucinations, delusions, disorganized speech or thinking, a loss of contact with reality, and a noticeable deterioration of functioning in everyday life.

View our full glossary

National Academies Press

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