Malaria

Plasmodium falciparum is one of the parasitic organisms carried by mosquitoes that cause malaria when infecting a human. This is only one of five types of plasmodium that cause malaria. However, Plasmodium falciparum is believed to cause as much as 40% of all malaria infections worldwide as well as the most severe presentation, including almost all fatal cases. (Wellems, Hayton & Fairhurst, 2009) Another 40% of malaria cases can be attributed to P. vivax, the remaining infections, until recent years were the result of infection with P. ovale and P. malariae. A new strand, P. knowlesi, previously thought only to infect certain primates in Southeast Asia, has recently emerged in the human population. (Wellems, Hayton & Fairhurst, 2009) Plasmodium falciparum is carried by mosquitoes and spread from human to human through bites from these insects. When the parasite first enters the blood stream it migrates to the liver where it matures in hepatocytes (liver cells). After it reaches full maturity, it enters the blood stream inside red blood cells; this can take as little as eight days or as long as a year, but in most infections it happens between ten days and four weeks. After 48 to 72 hours from RBC invasion by the parasite, the blood cell bursts allowing the parasite to spread and causing the infected individual to have severe bouts of anemia. In addition to anemia malaria can present with flu-like symptoms such as fever, chills, muscle pain, nausea, vomiting, and diarrhea, as well as, in more severe cases, jaundice, convulsions, coma or death. (Kumar, Abbas, & Fausto, 2005) Malaria is one of the leading causes of death worldwide, and is most prevalent in the tropics and subtropics; it can be seen in more temperate climates, but does not survive winter. A disease believed to be malaria was first described by the Chinese in 2700 BC; this disease was soon studied by cultures reaching from Asia to ancient Greece. The first treatment, artemisinin, believed to be discovered by the Chinese, was drawn from the plant that Americans know as wormwood. Quinine, comes from the bark of another tree called Cinchona, this remedy was discovered by the Spanish in the early 17th century when they arrived in the Americas. These two drugs remain some of the most effective treatments for malaria even today. (CDC, 2009) The control of malaria in the developed world has been greatly attributed to the use of Dichloro-diphenyl-trichloroethane (DDT). This insecticide was first synthesized in Germany and was discovered to kill malaria carrying mosquitoes; it was widely used to control malaria by the end of WWII. In addition, the CDC used this insecticide to eradicate malaria from the US. By 1951 the US was considered to be free of malaria. (CDC, 2009)Today, when Americans travel overseas to areas known to carry a high risk of malarial infection such as Africa, Southeast Asia, or South America, they are advised to seek prophylactic treatment from their physician. Physicians usually prescribe antibiotic treatment that starts one week before departure and lasts up to a month after the patient arrives back home. (CDC, 2009) While malaria is well controlled in the US, it still remains a threat worldwide. There remains a problem in Africa; children under five years of age from endemic regions account for the population with the most mortality due to malaria. In Pakistan, a recent epidemic was seen in Afghan refugee camps. This was attributed to the fact that the privately held health units were distributing sulfadoxine-pyrimethamine (SP) for infections caused by P. falciparum. This population showed resistance to the drug. The epidemic was ultimately controlled by a number of interventions including patient treatment, and treatment of mosquito nests with insecticide. (Leslie, Kaur, Mohammed, Kolaczinski, Ord & Rowland, 2009) References CDC. (2009) The History of Malaria, an Ancient Disease. Retrieved October 24, 2009 from http://www.cdc.gov/Malaria/history/index.htm. CDC. (2009) Travelers’ Health; the Yellow Book. Chapter 2: Malaria. Retrieved October 24, 2009 from http://wwwnc.cdc.gov/travel/yellowbook/2010/chapter-2/malaria.aspx#990. Kumar, V., Abbas, A. & Fausto, N. (2005) Robbins and Cotran Pathologic Basis of Disease. Chapter 8, Infectious Disease. Elsevier, Inc. Leslie, T., Kaur, H., Mohammed, N., Kolaczinski, K., Ord, R., Rowland ,M. (2009) Epidemic of Plasmodium falciparum malaria involving substandard antimalarial drugs, Pakistan, 2003. Emerging Infectious Diseases.15(11). Retrieved October 24, 2009 from http://www.cdc.gov/eid/content/15/11/1753.htm. Wellems, T., Hayton, K. & Fairhurst, R.(2009) The impact of malaria parasitism: from corpuscles to communities. Journal of Clinical Investigation. 119 (9), 2496-2505.