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

What You Need To Know About Infectious Disease

How Infection Works

Encountering Microbes

Microbes have inhabited the earth for billions of years and may be the earliest life forms on the planet. They live in every conceivable ecological niche—soil, water, air, plants, rocks, and animals. They even live in extreme environments such as hot springs, deep ocean thermal vents, and Antarctic ice. Indeed microbes, by sheer mass, are the earth’s most abundant life form and are highly adaptable to external forces. How does our modern lifestyle bring us into greater contact with infectious agents—the “bad” microbes? And when we encounter them, how do they get into our bodies?

New Meeting Places

New Meeting Places

Almost 2.4 million passengers, each a potential carrier of infection, travel daily by aircraft from the United States to international destinations.

International trade, expanded development into forest areas, and worldwide travel are just a few of the reasons why people are increasingly coming into contact with infectious agents. Learn more about these new encounters.

More about new meeting places

Entering the Human Host

Entering the Human Host

The most common vector for human infection is the mosquito, which transmits malaria, West Nile virus, dengue, chikungunya, yellow fever, and Zika.

What do sneezes, ticks, and raw meat have in common? They are all vehicles for pathogens (aka disease-causing microbes) to infect humans. Learn more about how infectious microbes spread.

More about entering the human host

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What do you know about infectious disease?

Due in large measure to the toll of infectious diseases, the gap in life expectancy between the richest and poorest countries now exceeds how many years?

  • Sorry, that’s incorrect.

    The gap in life expectancy between the richest and poorest countries now exceeds 40 years.

  • Sorry, that’s incorrect.

    The gap in life expectancy between the richest and poorest countries now exceeds 40 years.

  • Correct!

    The gap in life expectancy between the richest and poorest countries now exceeds 40 years.

  • Sorry, that’s incorrect.

    The gap in life expectancy between the richest and poorest countries now exceeds 40 years.

Infectious Disease Defined

Vector

An organism (usually an arthropod such as a flea, mosquito, or tick) that carries an infectious agent from one host to another.

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