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Mosquito-malaria theory (or sometimes mosquito theory) was a scientific theory developed in the latter half of the 19th century that solved the question of how malaria was transmitted. The theory basically proposed that malaria was transmitted by mosquitoes, in opposition to the centuries-old medical dogma that malaria was due to bad air, or miasma. The first scientific idea was postulated in 1851 by Charles E. Johnson, who argued that miasma had no direct relationship with malaria. Although Johnson's hypothesis was forgotten, the arrival and validation of the germ theory of diseases in the late 19th century began to shed new lights. When Charles Louis Alphonse Laveran discovered that malaria was caused by a protozoan parasite in 1880, the miasma theory began to subside. An important discovery was made by Patrick Manson in 1877 that mosquito could transmit human filarial parasite. Inferring from such novel discovery Albert Freeman Africanus King proposed the hypothesis that mosquitoes were the source of malaria. In the early 1890s Manson himself began to formulate the complete hypothesis, which he eventually called the mosquito-malaria theory. According Manson malaria was transmitted from human to human by a mosquito. The theory was scientifically proved by Manson's confidant Ronald Ross in the late 1890s. Ross discovered that malaria was transmitted by the biting of specific species of mosquito. For this Ross won the Nobel Prize for Physiology or Medicine in 1902.〔(【引用サイトリンク】url=http://www.nobelprize.org/nobel_prizes/medicine/laureates/1902/ross-facts.html )〕 Further experimental proof was provided by Manson who induced malaria in healthy human subjects from malaria-carrying mosquitoes.〔 Thus the theory became the foundation of malariology and the strategy of control of malaria. ==Early concepts== Malaria was prevalent in the Roman Empire, and the Roman scholars associated the disease with the marshy or swampy lands where the disease was particularly rampant. It was from those Romans the name "malaria" originated. They called it malaria (literally meaning "bad air") as they believed that the disease was a kind of miasma that was spread in the air, as originally conceived by Ancient Greeks. Then it was a medical consensus that malaria was spread due to miasma, the bad air. The first record of argument against the miasmatic nature of malaria was from a US Army physician William Crawford Gorgas. Gorgas wrote an article "Mosquital Origin of Malarial Disease" in ''Baltimore Observer'' in 1807, but it provoked no consequences. An American physician Charles Earl Johnson provided a systematic and elaborate arguments against miasmatic origin of malaria in 1851 before the Medical Society of North Carolina. Some of his important points were: #The delta of the Mississippi was a recorded healthy place although it has a nearby river, ponds, marshes and lots of stagnant water. #Labourers of North Carolina were the healthiest people of working classes in spite of their constant exposure to swamps, and drinking swamp water. #South American countries such as British Guiana and Brazil which were literally flooded with tropical swamps were free from malaria epidemics. #Java Island in Southeast Asia, a region known for epidemics, had luxuriant vegetation and agricultural fields, supplemented with hot and wet tropical climate, ideal for miasmatic disease, was but the healthiest part of Asia. #A highly polluted River Thames, which should cause miasmatic diseases, was but a good source of drinking water. #On the other hand, the driest regions such as Guinea in Africa, Spain, Malta, Gibraltar, and several states of America, were frequented with malarial fevers. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Mosquito-malaria theory」の詳細全文を読む スポンサード リンク
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