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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Mosquito-malaria theory | 3/3 | https://en.wikipedia.org/wiki/Mosquito-malaria_theory | reference | science, encyclopedia | 2026-05-05T10:06:59.882762+00:00 | kb-cron |
In 1894 Patrick Manson devised an ingenious procedure for detecting malarial parasites at different developmental stages from blood samples. This would later prove to be the tool for experimental proof of his theory. Manson demonstrated to and taught Ronald Ross the technique from which Ross became convinced of Laveran's germ theory. Trained and mentored by Manson, Ross returned to India in March 1895 to start his investigation. But to the dismay of Ross it was not an easy task. His first detection of malarial parasite from patients came only after two months of hard work. The disappointed Ross had to be encouraged by Manson calling the study as the "Holy Grail" of malaria research, and that Ross was the "Sir Galahad". After one and half years he made no significant progress. On 20 August 1897 he made a momentous discovery that some mosquitoes had malarial parasites in them. He had fed the blood of a malarial patient (Husein Khan) to different groups of mosquitoes four days before, and found that only one type (which he called "brown type" or more commonly "dappled-winged mosquitoes", not knowing the species, which in fact was Anopheles) acquired the malarial parasites in its stomach. This was the first evidence for Manson's theory that mosquito did carry the malarial parasite, and Ross would later famously call 20 August as "Malaria Day" (now adopted as World Mosquito Day). The second experimental evidence came in the mid-1898 when Ross demonstrated the transmission of bird malaria Proteosoma relictum (now Plasmodium relictum) between larks and mosquitoes, which he called "grey mosquitos" (which were Culex fatigans, but now renamed Culex quinquefasciatus). He showed that the mosquitoes ingested the parasites from infected birds and could infect healthy birds. He further discovered that the parasites developed in the stomach wall and were later stored in salivary glands of the mosquito. This was a conclusive evidence that malarial parasites were indeed transmitted by mosquitoes. In his report Ross concluded that:
These observations prove the mosquito theory of malaria as expounded by Dr Patrick Manson. On 9 July 1898 Ross wrote Manson:
Q.E.D. and [I] congratulate you on the mosquito theory indeed. Ross' scientific evidences were soon fortified by Italian biologists including Giovanni Battista Grassi, Amico Bignami, and Giuseppe Bastianelli, who discovered that human malarial parasite was transmitted by the actual biting (disproving one of Manson's hypotheses) of female mosquito. In 1899 they reported the infection of Plasmodium falciparum with the mosquito Anopheles claviger However the practical importance of validating the theory, i.e. control of mosquito vector should be an effective management strategy for malaria, was not realised by the medical community and the public. Hence in 1900 Patrick Manson clinically demonstrated that the bite of infected anopheline mosquitoes invariably resulted in malaria. He acquired carefully reared infected mosquitoes from Bignami and Bastianelli in Rome. His volunteer at the London School of Tropical Medicine, P. Thurburn Manson gave a detailed account of his malarial fevers and treatment after bitten by the mosquitoes. As he summarised, Manson's clinical trial showed that the practical solution to malaria infection was in:
avoiding the neighborhood of native houses where mosquitoes are abundant, destroying the habitats of mosquitoes, and protection from mosquito bite.
== References ==
== Further reading == Packard, Randall M. (2010). The Making of a Tropical Disease: A Short History of Malaria. Maryland, US: The Johns Hopkins University Press. ISBN 978-1-42-140175-1. Cook, G.C. (2007). Tropical Medicine: an Illustrated History of The Pioneers. Oxford, UK: Elsevier. ISBN 978-0-08-055939-1. Sherman, Irwin (2008). Reflections on a Century of Malaria Biochemistry. London: Academic Press. ISBN 978-0-0809-2183-9. Nye, Edwin R.; Gibson, Mary E. (1997). Ronald Ross : Malariologist and Polymath : a Biography. New York: St. Martin's Press, Inc. ISBN 0-312-16296-0. Ross, Ronald (1923). Memoirs, with a Full Account of the Great Malaria Problem and Its Solution. London: John Murray. Haynes, Douglas M. (2001). Imperial Medicine: Patrick Manson and the Conquest of Tropical Disease. Philadelphia: University of Pennsylvania Press. ISBN 978-0-81-223598-2. Lehrer, Steven (2006). Explorers of the Body : Dramatic Breakthroughs in Medicine from Ancient Times to Modern Science (2nd ed.). New York: iUniverse. p. 248. ISBN 978-0-595-40731-6.
== External links == Malaria: Past and Present The History of Malaria, an Ancient Disease History of Malaria: Scientific Discoveries The History of Malaria on Stamps