Definition: Fever is defined as a before-noon temperature of more than 37.2°C or 98.9°F or an after-noon temperature of more than 37.7°C or 99.9°F.Fever is an elevation in normal body temperature that occurs in connection with a raised hypothalamic set point.(15) Malaria is a mosquito-borne infectious disease of humans and other animals caused by parasite of the genus Plasmodium. It is a serious disease that causes a high fever and chills. It begins with a bite from an infected female Anopheles mosquito, which introduces the parasite through saliva into the circulatory system. In the blood, the parasite travels to the liver to mature and reproduce.(13)
Five species of Plasmodium can infect and be transmitted by humans. The vast majority of deaths are caused by P. falciparum and P. vivax, while P. ovale, and P. malariae cause a generally milder form of malaria that is rarely fatal. The disease is widespread in tropical and subtropical regions in a broad band around the equator, including much of Sub-Saharan Africa, Asia, and the Americas. Malaria is prevalent in tropical and subtropical regions because rainfall, warm temperatures, and stagnant waters provide habitats ideal for mosquito larvae. (13)
Prevalence: The World Health Organization has estimated that in 2010, there were 219 million documented cases of malaria. That year, between 660,000 and 1.2 million people died from the disease (roughly 2000–3000 per day),many of whom were children. Malaria is commonly associated with poverty and may also be a major hindrance to economic development. (13) Pathophysiology:
Malaria infection develops via two phases: one that involves the liver (exoerythrocytic phase), and one that involves red blood cells or erythrocytes (erythrocytic phase). When an infected mosquito pierces a person's skin to take a blood meal, sporozoites in the mosquito's saliva enter the bloodstream and migrate to the liver where they infect hepatocytes, multiplying asexually and asymptomatically for a period of 8–30 days.
After a potential dormant period in the liver, these organisms differentiate to yield thousands of merozoites, which, following rupture of their host cells, escape into the blood and infect red blood cells to begin the erythrocytic stage of the life cycle. The parasite escapes from the liver undetected by wrapping itself in the cell membrane of the infected host liver cell.
Some P. vivax sporozoites do not immediately develop into exoerythrocytic-phase merozoites, but instead produce hypnozoites that remain dormant for periods ranging from several months (7–10 months is typical) to several years. After a period of dormancy, they reactivate and produce merozoites. Hypnozoites are responsible for long incubation and late relapses in P. vivax infections. (13)