Plasmodium is a genus of parasites with over 200 known species, some of which are known to cause malaria. Approximately 10 Plasmodium species can cause disease in human beings. These parasites are native to the tropics and subtropics of the world and they are among the most studied parasites in the world, thanks to the significant risks posed by malaria infection worldwide.
These organisms are protists, simple-celled organisms that lack differentiated tissue structures. Protists can be found in watery environments all over the world and many have developed complex communal relationships like that seen with Plasmodium. This particular protist has a life cycle that includes spending time inside the bodies of both mosquitoes and mammal hosts. Treatment for malaria focuses on interrupting this lifecycle by either limiting mosquito populations, preventing mosquitoes from biting people, or preventing the organisms from reproducing inside the human body.
Malaria has been recognized and described in human populations since at least 5,000 BCE, when Chinese doctors discussed sets of symptoms that modern physicians recognize as malaria. There are a number of different forms of malaria, thanks to the fact that different Plasmodium species can cause the disease. Previous generations of doctors thought that malaria was caused by “bad air,” when in fact it is the result of being bitten by an infected mosquito in the genus Anopheles.
The life cycle of Plasmodium parasites is complex. When they enter the body of a mosquito, the parasites breed in the gut of the mosquito. Every time the mosquito bites, it releases parasites into the bloodstream of the victim. The parasites make their way into the liver where they multiply and then reenter the bloodstream, attacking red blood cells and causing symptoms like fever, chills, fatigue, and weakness. Left untreated, some cases of malaria can be fatal because the infection can lead to significant organ and brain damage.
There are medications available to treat malaria. Doctors began using quinine in the 1600s and today a broad spectrum of antimalarial drugs are available, although some are very expensive. Understanding how the disease is incubated and transmitted had led to a range of preventative measures including the use of insect nets and sprays to prevent people from being bitten along with prophylactic drugs that are designed to kill any Plasmodium species that manage to enter the body. People who travel to the tropics are strongly encouraged to visit a doctor before they go to get malaria prophylactics and tips on preventing malaria infection.