Patrick Manson came to Shanghai following in the footsteps of his older brother, who had already come and established himself in the region. During that time, London had a solid foothold in China after Hong Kong had been ceded to them, and Western influence in the region was growing.
He joined the medical corps as an officer in the Customs Service of Formosa, a region that would later be known as Taiwan. It was there that he began his career in tropical medicine, which would lead to some important medical discoveries.
His official duties involved checking incoming ships, where he learned stunning record keeping. This would come in handy as he began to treat native patients. He noticed that some of them suffered from severe inflammation of the lower extremeties, which is caused by filaria. This tiny worm causes elephantiasis.
His breakthrough came from an observation he made in the patient’s blood. During the day, the parasites could not be seen, but they were plainly visible at night. He used his gardener as a test subject, allowing a mosquito to feed on him at night. This was how he discovered the mosquito’s digestive juices actually helped the worm grow. This important breakthrough gave rise to the mosquito-malaria theory, which is the basis of malariology today.
Manson moved to Hong Kong in 1883 to continue his work, becoming the first person to import cows from Scotland. Under the funding of the London Missionary Society, he founded the Hong Kong College of Medicine for Chinese. That school would graduate Sun Yat-Sen, the man who would lead the revolution to topple the Qing Dynasty and establish the Republic of China.