On Aug. 20, 1897, Sir Ronald Ross made his landmark discovery. While dissecting the stomach tissue of an anopheline mosquito fed four days previously on a malarious patient, he found the malaria parasite and went on to prove the role of Anopheles mosquitoes in the transmission of malaria parasites in humans.

In 1895, Ross was based in Sekunderabad, India, where he embarked on his quest to determine whether mosquitoes transmitted malaria parasites of man. For two years his studies were clouded by observations on what we now know to be insusceptible mosquito species.

in July 1897 he reared 20 adult “brown” mosquitoes from collected larvae. Following identification of a volunteer (Husein Khan) infected with crescents of malignant tertian malaria and the expenditure of 8 annas (one anna per blood-fed mosquito!), Ross embarked on a four-day study of the resultant engorged insects.

This “compact” study was written up and submitted for publication. Ross’s paper was published by the British Medical Journal on 18 December 1897.

Sir Ross received the Nobel Prize for Physiology or Medicine in 1902 for his work on the transmission of malaria