[ muh-lair-ee-uh ]
/ məˈlɛər i ə /
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Pathology. any of a group of diseases, usually intermittent or remittent, characterized by attacks of chills, fever, and sweating: formerly supposed to be due to swamp exhalations but now known to be caused by a parasitic protozoan, which is transferred to the human bloodstream by a mosquito of the genus Anopheles and which occupies and destroys red blood cells.
Archaic. unwholesome or poisonous air.
Should you take this quiz on “shall” versus “should”? It should prove to be a quick challenge!
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Origin of malaria

1730–40; <Italian, contraction of mala aria bad air


Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022


What is malaria?

Malaria is the collective name of a potentially fatal group of diseases caused by parasitic organisms spread through bites of a particular mosquito.

Symptoms of malaria include periods of fever, chills, and sweating followed by respiratory problems and organ failure and, finally, death. Malaria is preventable and, if it’s caught early, it is curable.

Malaria is caused by a parasitic, microscopic organism known as a protozoan. At least four members of the genus Plasmodium are known to cause malaria in humans. These are P. falciparum, P. malariae, P. ovale, and P. vivax. P.knowlesi may also cause malaria.

These protozoa enter the bloodstream through a bite from several different species of female mosquitoes from the genus Anopheles. The protozoa are more likely to live inside a mosquito with a long life and are more likely to enter humans if the mosquito has a tendency to bite humans instead of animals.

The majority of species of Anopheles mosquitoes that fit both categories are native to Africa. For this reason, over 90 percent of the world’s malaria cases occur in Africa. In 2018, there were 228 million cases of malaria, with 405 thousand deaths.

Why is malaria important?

The first records of the word malaria come from around 1730. It is a contraction of the Italian mala aria, meaning “bad air.” People once thought malaria was caused by poisonous air, but we now know this is not true.

Children under 5 years old are the most at risk of dying from malaria. This age group alone accounted for 274,000 (67 percent) of malaria deaths in 2018.

The biggest factor in the infection rate of malaria is the number of mosquitoes that spread the protozoa. Climate and rainfall have a large impact on the survival of the mosquitoes, so weather patterns actually play a big role in how many people are likely to be infected with malaria. Being repeatedly bitten by these mosquitoes can also lead to a partial immunity to the disease, which is why young children who have never been bitten are most vulnerable.

Did you know … ?

The fact that malaria is caused by protozoa spread by mosquitoes was discovered by British surgeon Sir Ronald Ross. Ross dedicated much of his life to the prevention of malaria and was awarded the Nobel Prize in Medicine in 1902 for his work. In addition to medicine, Ross was also interested in poetry, and he actually wrote multiple poems about his war against malaria.

What are real-life examples of malaria?

This image shows a computerized recreation of red blood cells infected with malaria-causing protozoa. You can actually see the protozoa in several of the cells.


Malaria is a deadly disease that kills hundreds of thousands of people every year.

What other words are related to malaria?

Quiz yourself!

Malaria is caused by protozoa entering the bloodstream through bites from:

A. ticks
B. mosquitoes
C. fleas
D. spiders

How to use malaria in a sentence

British Dictionary definitions for malaria

/ (məˈlɛərɪə) /

an infectious disease characterized by recurring attacks of chills and fever, caused by the bite of an anopheles mosquito infected with any of four protozoans of the genus Plasmodium (P. vivax, P. falciparum, P. malariae, or P. ovale)

Derived forms of malaria

malarial, malarian or malarious, adjective

Word Origin for malaria

C18: from Italian mala aria bad air, from the belief that the disease was caused by the unwholesome air in swampy districts
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for malaria

[ mə-lârē-ə ]

An infectious disease characterized by cycles of chills, fever, and sweating, caused by the parasitic infection of red blood cells by a protozoan of the genus Plasmodium, which is transmitted by the bite of an infected female anopheles mosquito.jungle fever paludism swamp fever

Other words from malaria

ma•lari•al null null adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for malaria

[ mə-lârē-ə ]

An infectious disease of tropical areas caused by the parasitic infection of red blood cells by a protozoan of the genus Plasmodium, which is transmitted by the bite of an infected female mosquito. Malaria is characterized by recurrent episodes of chills, fever, sweating, and anemia and is endemic in Africa, Central America, and much of Southern Asia and northern South America.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for malaria

[ (muh-lair-ee-uh) ]

An infectious disease caused by a parasite that is transmitted by the bite of an infected mosquito. Persons suffering from malaria experience periodic episodes of chills and fever.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.