Affecting humans across all continents for centuries, this debilitating disease was long believed to be caused by unhealthy vapours, which gave its name - malaria (from Latin for bad air).

While several scientists in the 19th century began zeroing in on its actual cause, the definitive proof was obtained by a British doctor in India who paid a volunteer eight annas for being bitten the same number of times by the suspected vector.And Ronald Ross, who would be knighted and win the second Noble Prize for Medicine (not without controversy), celebrated his discovery by writing a poem to his wife - ending "I know this little thing/A myriad men will save/O Death, where is thy sting? Thy victory, O Grave?" (the last lines a reworking of the hymn "Abide With Me").Though the discovery in August 1897 was built on work of many scientists around the world since the beginning of the century, Ross (1857-1932), whose 160th birth anniversary is on Saturday (May 13), was also a mathematician, novelist, dramatist, poet, amateur musician, composer and artist though it is as a persistent -- and impulsive medical researcher he is most famous. 

Born in Almora in the family of a British general, he studied in Britain where he proved to be exceptionally good in mathematics and wanted to be a writer but was admitted to St Bartholomew's Hospital Medical College by his father in 1874.Though he spent most of his time writing poems and plays, he did pass his examinations to become a surgeon in 1880. He entered the Indian Medical Service in 1881 and was posted to various areas including Madras, Bangalore (where in 1883 he noticed mosquitoes could be controlled by limiting their access to water and suffered from malaria himself), Baluchistan and even the Andaman Islands. 

His interest in malaria was sparked by a meeting with Sir Patrick Manson, the "father of tropical medicine", during a spell of leave in London in 1894 and they discussed findings of Charles Laveran, a French army surgeon in Algeria who had discovered parasitical cells in the blood of a patient.It was in Secundrabad, where he was posted in 1895, that Ross began his research to ascertain whether mosquitoes transmitted malaria parasites, but for years, made no headway."Eventually 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.

"Imagine today sending an article to a leading medical journal 'in which you describe observations on novel objects found on the midguts of just two 'brown' mosquitoes, obtained from larvae of natural origin, that you had previously fed on a naturally infected patient - with no appropriate controls and no replicates! What hope would it have of getting past the editor and reviewers," asked Robert Sinden in an article on Ross and his discovery in the January 2014 bulletin of the World Health Organisation.Sinden, of the Faculty of Natural Sciences in London's Imperial College, however goes on to say that despite the "perceived inadequacies of the study design, it is difficult to overstate the importance of Ross's paper: the award of a Nobel Prize hardly does justice to the subsequent impact of his conclusions", especially in identifying the most vulnerable stage in the parasite's lifecycle for effective intervention.But that was not the limit of Ross' contribution to fighting this -- or other dreaded diseases.

Before resigning from the IMS in 1899 after trying unsuccessfully to find the cause of kala azar in eastern India, he subsequently joined the Liverpool School of Tropical Medicine and continued to work on prevention of malaria in different parts of the world. He also developed mathematical models for the study of malaria epidemiology.Ross, who won the Nobel in 1902 (after a tussle with Italian researchers who had also identified the cause in 1897), went on to set up the Ross Institute and Hospital for Tropical Diseases in 1926 which he headed till his death. 

But despite his path-breaking work, malaria, which due to its high mortality and morbidity levels, has had the greatest selective pressure on the human genome in recent history, still exerts its malignant effect across some of the world's poorest regions -- though some hope lies in a vaccine due to be tested in Africa the next year.