[10][11] In 1894, Manson formulated the mosquito-malaria theory to explain the hitherto unknown process of the transmission of malaria, one of the deadliest parasitic diseases in humans.
[12][13] The theory was experimentally proved by Ronald Ross in India who received the Nobel Prize in Physiology or Medicine in 1902 for the discovery.
"[3] The Royal Society of Tropical Medicine and Hygiene, (RSTMH) was founded in 1907 by Sir James Cantlie and George Carmichael Low.
[15] Sir William Boog Leishman, Major-General of the Army Medical Services, felt that the London School of Hygiene and Tropical Medicine, an institute Manson had established, should contain a respectable portrait of the founder.
[16] After Manson's death in 1922, the surplus money was given to the RSTMH to institute an award for scientists with outstanding contributions to tropical medicine and hygiene.
The medal was made in bronze having Manson's portrait on one side and the reverse an inscription, "London School of Tropical Medicine.
[19][20] In 1894, he discovered a protozoan parasite (later named after him as Trypanosoma brucei) that caused animal sleeping sickness (nagana) in Zululand.