Patrick Manson was inspired by his elder brother, David Manson, who worked in
Shanghai in medical service, to join medical officer post in the Customs Service of Formosa (now
Taiwan). Manson traveled to Formosa in 1866 as a medical officer to the
Chinese Imperial Maritime Customs, where he started a long career in the research of tropical medicine. His official daily duty involved inspecting ships docked at the port, checking their crews and keeping the
meteorological record. He also attended to Chinese patients in a local missionary hospital where he was exposed to a wide variety of tropical diseases for his postgraduate training without any supervision. His only research tool was a combination of clinical skill, hand lens and good record keeping. He was in good terms with the native Chinese, learning
Mandarin and befriending them. However, due to political conflict between China and Japan over the occupation of the island, he was advised by the British Consul to leave. After 5 years in Formosa, he was transferred to
Amoy, on the Chinese coast where he worked for another 13 years. Once again he again served the local Chinese patients at the
Baptist Missionary Society's Hospital and Dispensary for the Chinese. His brother David joined him for 2 years.
Discovery He spent his early years researching filaria (a small worm that causes
elephantiasis). Manson focused his time on searching for filaria in blood taken from his patients. From this he began to work out the life cycle of filaria and through painstaking observation discovered that the worms were only present in the blood during the night and were absent during the day. He conducted experiments on his gardener, Hin Lo, who was infected with filaria. He would get mosquitoes to feed on his blood while he slept and then dissect the mosquitoes filled with Hin Lo's blood.
"I shall not easily forget the first mosquito I dissected. I tore off its abdomen and succeeded in expressing the blood the stomach contained. Placing this under the microscope, I was gratified to find that, so far from killing the Filaria, the digestive juices of the mosquito seemed to have stimulated it to fresh activity." Manson observed that filaria only developed as far as an embryo within the human blood and that the mosquito must have a role in the life cycle. Through these early experiments he started to hypothesise about the role of mosquitoes and the spread of disease. That the mosquito (
Culex fatigans, now
Culex quinquefasciatus) was the
intermediate host of the filarial parasite (
Wuchereria bancrofti) was a medical breakthrough in 1877. His experimental results were published in the China Customs Medical Report in 1878, and relayed by Spencer Cobbold to the
Linnean Society in London. In this article he states,
"the mosquito, having been shown to be the agent by which the filaria is removed from the human blood vessels, this or similar suctorial agent must be the agent which removes from the human blood vessels those forms of the malaria organism which are destined to continue the existence of this organism outside the body." He then proposes,
"the hypothesis I have ventured to formulate seems so well grounded that I for one, did circumstances permit, would approach its experimental demonstration with confidence. The necessary experiments cannot for obvious reasons be carried out in England, but I would commend my hypothesis to the attention of medical men in India and elsewhere, where malarial patients and suctorial insects abound." Sir Ronald Ross approached Manson in London and went on to prove this theory. The subsequent correspondence between Ross and Manson is documented as one of the most legendary collaborations in the history of medicine. Manson's theory was finally confirmed by Ross in 1898 who described the full life cycle of the malarial parasite (of birds) inside the female mosquito. Ross won the
Nobel Prize for Physiology or Medicine in 1902 for this discovery. Both Manson and
Laveran were also nominated for the Nobel prize. During his acceptance speech, Ross controversially did not acknowledge Manson as his primary mentor. The subsequent fall out between these two great men is well documented in the book
The Beast in the Mosquito: The Correspondence of Ronald Ross and Patrick Manson. Manson also demonstrated a new species of
Schistosoma (
Bilharzia) known as
Schistosoma mansoni. In 1882, he discovered
sparganosis, a parasitic infection caused by the tapeworm
Spirometra. ==In Hong Kong==