Ronald Ross Biography (1857-1932)
Born in Almora, India, Ronald Ross spent much of his career in the Indian Medical Service. Because malaria was a devastating health problem in India, he began to study its cause in 1890. His research on the life-cycle of the parasite which causes the illness was instrumental in the modern understanding thatmalaria is a mosquito-borne disease.
It had long been thought that diseases were spread by odors, and that malariawas caused by the vapors produced in swamps. In 1880, Charles Louis AlphonseLaveran's (1845-1922) observations that the blood of malaria patients contained the pigmented bodies of parasites suggested an alternative cause. In 1894, Sir Patrick Manson (1844-1922) demonstrated the truth of this observation to Ross and suggested that mosquitos were responsible for transmitting these parasites to humans. Ross set out to investigate the life-history of the parasite and to test Manson's theory.
Progress was slow, but on August 16, 1897, Ross allowed ten Anophelesmosquitos--a species new to him--to feed on a malaria patient who had agreedto serve as a volunteer. Over the next few days, Ross dissected the mosquitosas usual, looking for some sign of malarial parasites acquired from the patient. He found nothing unusual, and by August 20 only two mosquitos were left.
He had decided to dissect one of these last Anopheles, but grew so discouraged when he found nothing unusual that he almost did not finish. But when he began to examine the mosquito's stomach tissue, he found several cells too small to be ordinary mosquito stomach cells. Inside each cell was a cluster of black granules just like those of Laveran's parasites.
Ross realized that if these were in fact the malarial parasites he had been seeking, they should continue to grow within the mosquito. When he dissected his last mosquito the next day and found still larger parasites in its stomachtissue, he knew he had discovered the parasite's stage of development whichwas the link between humans and mosquitos, and he named August 20 "Mosquito Day."
A published novelist, poet, and playwright, he added a set of verses inspiredby his discovery to his poem "Exile":
This day relenting God Hath placed within my hand A wondrous thing; and God Be praised. At his command, Seeking His secret deeds With tears and toiling breath, I find thy cunningseeds, O million-murdering Death. I know this little thing A myriad men willsave. O Death, where is thy sting? Thy victory, O Grave?
The next step in his research was to demonstrate the mode of transmission ofthe parasite from mosquito to human. A transfer within the Service preventedfurther work with humans, but Ross was able to study avian malaria in caged birds. He followed the parasites from an infected bird into the stomach of a Culex ( Aëdes) mosquito which had fed on the bird, and from thereto the mosquito's salivary glands. The bite of this mosquito then transmittedthe malarial parasite to another bird. The Italian scientist, Giovanni Grassi (1854-1925), demonstrated the same process between Anopheles and humans in 1898.
Devoting himself to the promotion of research into malaria and the stimulation of measures to control it, Ross published many reports based on the principle that, to eradicate malaria, mosquitos must be isolated from infected humans. He received the Nobel Prize in physiology or medicine in 1902, was knighted in 1911, served as a consultant in malaria to the War Office during World War I, and founded the Ross Institute of Tropical Hygiene in 1926.