polio

noun

po·​lio ˈpō-lē-ˌō 

: an infectious disease especially of young children that is caused by the poliovirus

Note: Individuals infected with the poliovirus are often asymptomatic. In approximately 25% of cases, polio presents as a mild to moderate illness marked by headache, fever, sore throat, vomiting, diarrhea, and fatigue. Polio affects the central nervous system only infrequently with inflammation and sometimes destruction of the motor neurons in the gray matter of the spinal cord and brain stem. Central nervous system involvement results in temporary or permanent muscle weakness or motor paralysis especially of the limbs and typically the legs. Polio may become life-threatening when paralysis affects the muscles involved in breathing and swallowing.

And the dreaded disease polio was virtually eliminated in 1955 when the Salk vaccine was approved for public use.

—Mary Beth Norton et al.

The longstanding quest to eradicate polio is attracting a new injection of funds from donors around the world, as health leaders grapple with obstacles from ridding conflict areas of the virus to a shortage of vaccine.

—Betsy McKay

called also infantile paralysis, poliomyelitis

see post-polio syndrome

polio-like

ˈpō-lē-ˌō-ˌlīk 

adjective

or poliolike

a polio-like disease

polio-like paralysis

Examples of polio in a Sentence

Recent Examples on the Web

Before the polio vaccine was developed, the virus killed or paralyzed nearly half a million people worldwide each year in the mid-20th century, according to the World Health Organization. —Cheyenne Haslett, ABC News, 29 Jan. 2025

The following year, Aaron Siri, a lawyer working closely with Kennedy, petitioned the FDA to revoke approval of the polio vaccine, the Times reported in December. —Jamie Ducharme, TIME, 29 Jan. 2025

Work combatting new disease outbreaks, eradicating diseases such as polio, and supporting contraception seems to be excluded from the waiver. —Atul Gawande, The New Yorker, 29 Jan. 2025

Vaccines have helped eradicate countless diseases, like polio, and increase life expectancy, but those benefits are hard to properly visualize or quantify, Polite said. —Alexandra Kukulka, Chicago Tribune, 26 Jan. 2025

Word History

Etymology

short for poliomyelitis

First Known Use

1911, in the meaning defined above

Phrases Containing polio

• polio virus
• post-polio syndrome

Kids Definition

polio

noun

po·​lio ˈpō-lē-ˌō 

: poliomyelitis

Medical Definition

polio

noun

po·​lio ˈpō-lē-ˌō 

: an infectious disease especially of young children that is caused by the poliovirus

Note: Individuals infected with the poliovirus are often asymptomatic. In approximately 25% of cases, polio presents as a mild to moderate illness marked by headache, fever, sore throat, vomiting, diarrhea, and fatigue. Polio affects the central nervous system only infrequently with inflammation and sometimes destruction of the motor neurons in the gray matter of the spinal cord and brain stem. Central nervous system involvement results in temporary or permanent muscle weakness or flaccid paralysis of muscles especially of the limbs and typically the legs. Polio may become life-threatening when paralysis affects the muscles involved in breathing and swallowing.

Thanks to the Salk and Sabin vaccines, the specter of crippling polio that once made summers an apprehensive time for Americans has long since passed.

—People Weekly

While the last case of naturally occurring polio in the United States was in 1979, the disease remains prevalent in other areas of the world.

—Evan Johnson, The Addison County (Vermont) Independent

called also infantile paralysis, poliomyelitis

see post-polio syndrome