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

What You Need To Know About Infectious Disease

An electron micrograph of an influenza virus, showing details of its structure.

Credit: Cynthia Goldsmith/CDC

Viruses

Viruses are tiny, ranging in size from about 20 to 400 nanometers in diameter. Billions can fit on the head of a pin. Some are rod shaped; others are round and 20 sided; and yet others have fanciful forms, with multisided “heads” and cylindrical “tails.”
Viruses are responsible for a wide range of diseases, including the common cold, measles, chicken pox, genital herpes, and influenza.
Viruses are simply packets of nucleic acid, either DNA or RNA, surrounded by a protein shell and sometimes fatty materials called lipids. Outside a living cell, a virus is a dormant particle, lacking the raw materials for reproduction. Only when it enters a host cell does it go into action, hijacking the cell’s metabolic machinery to produce copies of itself that may burst out of infected cells or simply bud off a cell membrane. This lack of self-sufficiency means that viruses cannot be grown in artificial media for scientific research or vaccine development; they can be grown only in living cells, fertilized eggstissue cultures, or bacteria.
 
Viruses are responsible for a wide range of diseases, including the common cold, measleschicken pox, genital herpes, and influenza. They also cause many of the emerging infectious diseases, among them AIDS, Ebola, and Zika.
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Disease Watchlist

What do you know about infectious disease?

Which of the following is an effective way to protect yourself against infectious disease?

  • Sorry, that’s incorrect.

    All of the above can help prevent infectious disease. Other behaviors, such as exercising caution around wild and unfamiliar domestic animals, avoiding insect bites, practicing safe sex, and being vigilant about disease threats while traveling abroad, can also reduce the risk of infection.

  • Sorry, that’s incorrect.

    All of the above can help prevent infectious disease. Other behaviors, such as exercising caution around wild and unfamiliar domestic animals, avoiding insect bites, practicing safe sex, and being vigilant about disease threats while traveling abroad, can also reduce the risk of infection.

  • Sorry, that’s incorrect.

    All of the above can help prevent infectious disease. Other behaviors, such as exercising caution around wild and unfamiliar domestic animals, avoiding insect bites, practicing safe sex, and being vigilant about disease threats while traveling abroad, can also reduce the risk of infection.

  • Correct!

    All of the above can help prevent infectious disease. Other behaviors, such as exercising caution around wild and unfamiliar domestic animals, avoiding insect bites, practicing safe sex, and being vigilant about disease threats while traveling abroad, can also reduce the risk of infection.

Infectious Disease Defined

Staph Infection

An infection caused by any one of several harmful species or subspecies of bacteria of the genus Staphylococcus.

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National Academies Press

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