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Malaria: A Devastating Public Heath Concern


Malaria: The Deadly Disease

Background on the Disease
Anopheles mosquitos: The Vector
Plasmodium: The Parasite
Symptoms and Diagnosis
Treatment and Prevention
Economic Consequences
"About 40% of the world's population - about two billion people - are at risk in about 90 countries and territories. 80 to 90% of malaria deaths occur in sub-Saharan Africa where 90% of the infected people live." [2]

 Malaria or the symptoms of malaria have been noted for more than 4,000 yrs.  The name is derived from the Italian for bad air- mal’aria. By the 4th century BCE malaria was widely recognized in Greece and can be attributed to the decline of many rural and city-state populations.  The malaria parasite was discovered in 1880 and in 1897 Ronald Ross was first to demonstrate that mosquitoes could become infected with malaria after feeding on an infected patient.  This required that the parasite have a sporogonic cycle.  Shortly thereafter in 1899 the mode of transmission was demonstrated when scientists showed that a mosquito that fed on a patient positive for malaria could transmit the disease to a healthy volunteer by feeding on them.[1]  It is a vector borne disease, which is transmitted by mosquitoes.  This occurs when a mosquito feeds on an infected patient, acquiring the parasite, which it can then transfer to another human.  The infected person will then test positive for malaria and will show signs of the disease when the parasite has infected the liver and caused the cells to burst, resulting in parasite throughout the bloodstream. It is during one of these fever spells when the parasite can be easily found in the blood that another mosquito can feed, acquire the parasite and then repeat the cycle.  Malaria can either be prevented, by not allowing the mosquito to infect the human in the first place, or it can be treated once the person is already infected, thus targeting the parasite. 

      

http://www.pbs.org/wgbh/rxforsurvival/series/diseases/malaria.html (4/29/06); http://www.nature.com/doifinder/10.1038/nm0903-1097b  (4/26/06)
    

     Outbreaks of malaria are closely aligned with the breeding grounds of the vector, the Anopheles mosquito.  The Anopheles mosquito is a passive carrier of the disease.  It allows the detrimental parasite, Plasmodium, to undergo its full life cycle and enter into the blood of the mosquito.  Malaria can only be transmitted in regions where the parasite can complete its life-cycle before the mosquito dies of natural causes.  Thus, malaria is not a disease that can be transmitted directly from person to person, but requires the mosquito intermediate.

 
[2] http://archive.idrc.ca/books/reports/1996/01-07e.html                                                

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