I was first introduced to malaria through the “Little House” books by Laura Ingalls Wilder (loved these as a kid!). In Little House on the Prairie, the entire Ingalls family lives near a mosquito-infested creek, and comes down with what they call “fever ‘n’ ague.” They experience chills, fever, and aches all over, and they all nearly die from the disease. If not for their dog Jack, the kind Dr. Tan, and their neighbor Mrs. Scott, they probably would have. At the time, they did not know that mosquitoes transmitted the disease. Mrs. Scott and Ma Ingalls believe that the sickness was caused by the watermelons grown by the creek bottoms, because everyone who had eaten the watermelons had gotten sick. Pa Ingalls believes it was from “breathing the night air” (“malaria” is derived from the Italian phrase “mala aria,” which literally means “bad air”). Turns out they were all wrong, but the protozoan culprit of malaria was not discovered until after the events of this book.
Malaria in humans is caused by five parasitic species of the genus Plasmodium. Two species cause the vast majority of disease — P. falciparum and P. vivax. These protozoa are spread through infected female Anopheles mosquitos, which transmit the parasites when they bite people for blood meals. Symptoms of malaria include fever, chills, sweats, headaches, nausea, vomiting, body aches, and malaise, which may not be immediately recognizable as malaria in a country where malaria is not common. Malaria can progress in severity and result in life-threatening conditions such as abnormal blood clotting, severe anemia, cerebral malaria, acute respiratory distress, and organ failure.
Currently, the majority of malaria cases occur in sub-Saharan Africa. In 2018, the WHO African region contained 93% of all malaria cases and 94% of all malaria deaths. There were 228 million cases worldwide in 2018, and which caused 405,000 deaths. Tragically, 67% (272,000) of these deaths occurred in children under 5.
Malaria is not talked about very much in the United States. I only remember it being brought up in biology classes to help demonstrate the concept of heterozygote advantage in sickle cell anemia. This is likely because malaria is no longer a significant issue in the United States and other developed countries, much like many other infectious diseases. Instead, we focus on issues like heart disease, cancer, obesity, and diabetes, which have become the biggest health problems in the country. As a result, many people forget how deadly it is and how much of a problem it remains in other parts of the world, where it may be a top 5 cause of death. Although we have greatly reduced the number of malaria cases over the past several decades, it has not yet been eradicated, and progress is slower than initially hoped by WHO back in 1955, at the beginning of their Global Malaria Eradication Program.
In researching this disease, the most interesting part was learning about the impact of malaria on U.S. history, because I never really associated malaria with the United States. Although malaria is not an endemic problem today, it was at one point, and had significant effects on American history. Species of Plasmodium were brought to the New World through European settlers and African slaves. Later, malaria affected hundreds of thousands of soldiers during the Civil War, and may have even influenced the outcome of the war. For example, the Union had access to the drug Quinine to treat malaria, but due to naval blockades against the South, the Confederacy did not. Malaria was also a huge obstacle to American soldiers in the Pacific Theater of WWII. The CDC (then called the Communicable Disease Center) was established in 1946, primarily to prevent the spread of malaria in the United States. If you have ever wondered why the CDC is headquartered in Atlanta, Georgia, it is because the South is where malaria had the biggest stronghold due to the climate. Malaria was eliminated as a major public health problem in the United States by the end of the 1940s, although we still have about 2,000 cases per year due to “imported” malaria.
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