Washing with regular soap is considered the most important way to prevent disease transmission. Routine consumer use of residue-producing antibacterial products has no added benefit and may actually contribute to antibiotic resistance.

In 2008, more than 33 million people worldwide were infected with HIV (human immunodeficiency virus). In that same year, an estimated 2 million people died from AIDS (acquired immunodeficiency syndrome), the final stage of HIV infection.

In 2008, more than 33 million people worldwide were infected with HIV (human immunodeficiency virus). In that same year, an estimated 2 million people died from AIDS (acquired immunodeficiency syndrome), the final stage of HIV infection.

Because strep throat is caused by a bacterium called Streptococcus pyogenes, it is treatable with antibiotics but not antivirals. Currently there is no vaccine available to prevent strep throat.

Because strep throat is caused by a bacterium called Streptococcus pyogenes, it is treatable with antibiotics but not antivirals. Currently there is no vaccine available to prevent strep throat.

Because strep throat is caused by a bacterium called Streptococcus pyogenes, it is treatable with antibiotics but not antivirals. Currently there is no vaccine available to prevent strep throat.

Not all microbes are harmful to humans. In fact, many of them protect us, helping our bodies function properly and competing with harmful organisms in an eternal contest for habitable space in or on our bodies. Although the microorganisms that cause disease often receive more attention, most microorganisms do not cause illness.

Since the beginning of the 20th century the number of people in the world has more than quadrupled—from 1.6 billion to nearly 7 billion—and world population is expected to rise to well over 9 billion by 2050.

Since the beginning of the 20th century the number of people in the world has more than quadrupled—from 1.6 billion to nearly 7 billion—and world population is expected to rise to well over 9 billion by 2050.

Growing evidence does suggest that infections are behind many chronic diseases once thought to be caused by genetic, environmental, or lifestyle factors, including peptic ulcers and cervical, liver, and gastric cancers.

Almost 70% of all the antibiotics produced in the United States is added to animal feeds—not to fend off disease but to boost growth. These non-therapeutic uses of antibiotics are a perfect way to cultivate microbes that are resistant to antibiotics.

Almost 70% of all the antibiotics produced in the United States is added to animal feeds—not to fend off disease but to boost growth. These non-therapeutic uses of antibiotics are a perfect way to cultivate microbes that are resistant to antibiotics.

An estimated 1.8 million airline passengers cross international borders daily, creating routes by which human infections can radiate around the world within hours.

An estimated 1.8 million airline passengers cross international borders daily, creating routes by which human infections can radiate around the world within hours.

Most infectious diseases are impacted by changes in the environment. Malaria, dengue, and viral encephalitis infections, for example, are highly sensitive to environmental changes.