Friday, May 12, 2006


Originally uploaded by dalbhat.
Yesterday I drove by a small gate across from Nandan where a small plaque hangs to introduce the location of the laboratory where Sir Ronald Ross, a British physician and entomologist noted for identifying the links between mosquitoes and malaria, made his mosquito breakthrough.

Ross was born in India in 1857. His father was a soldier who eventually became a general in the Indian army. Ross lived in India until he was eight ,when he was sent away to boarding school in Southampton, England.

In 1874 he became a medical student at St Bartholomew's Hospital in London. In 1879 Ross just managed to pass his Royal College of Surgeons exam. This meant that he could only practice as a ship's surgeon, which he did for a couple of years until he passed an exam for the Society of Apothecaries. This meant that in 1881 Ross could join the British-Indian army medical services and eleven years later he began investigating the transmission and control of malaria.

When Ross was a small boy in India, he saw many people fall ill with malaria. At that time in India one million people died every year from malaria. Because of this, malaria was known as the "King of diseases". While Ross was in India his father fell seriously ill with malaria, but fortunately recovered. This prompted an interest in the disease for him.

When Ross returned to India as part of the British-Indian medical services he was sent to Madras where he found that a large part of his work was treating soldiers ill with malaria. The treatment was with quinine which was quite successful, but many died because they failed to get treatment.

At that time it was believed that malaria was caused by breathing in bad air in a hot, marshy country. In fact the name malaria comes from the Italian words male which means " bad" and aria which means "air". However, Ross had strong doubts that bad air was the cause of malaria.

In 1883, Ross obtained the post of Acting Garrison Surgeon at Bangladore. Accommodation was provided, but while Ross found the bungalow pleasant to live in, he was irritated by the large numbers of mosquito which constantly buzzed around the rooms. He also noticed that there seemed to be more mosquito in his bungalow than in others and that there was a particularly large swarm around a water tub outside the window. When Ross looked in the tub he saw lots of "wriggling" grubs which he identified as mosquito larvae. The mosquito were breeding in the water. Ross emptied the water and found that the number of mosquito reduced. This started him thinking that if the places where mosquito bred were removed it might be possible to eliminate them completely.

Between 1881 and 1894 Ross was to have many postings as a doctor throughout India. During this time he also wrote a number of adventure stories which became very popular.

While he was posted in India, Ross returned to England a number of times and in 1889, on leave in England he took a course in bacteriology. This was a new discipline and gave him an opportunity to use a microscope.While he was in England he met and married his wife Rosa.

In 1894-95 Ross returned to England again for a long holiday and while there he discussed his theories with Dr Patrick Manson a specialist in tropical diseases. They also discussed the work of Laveran, a French doctor who had recently identified parasites called Plasmodium in the blood of people from North Africa who had malaria. Dr Manson and Ross then examined some tiny drops of blood taken from sailors who had come from Africa through a microscope. These showed the Plasmodium parasite infecting the red blood cells.

But, how did the malaria get from sick people into healthy people? It did not seem to be transmitted by the usual ways.

When, in 1895 Ross returned to India he had an increased interest in establishing the link between mosquitoes and malaria and carried out a series of experiments to prove this theory.

In March 1897 Ross was posted to Ootacamund, where he fell ill with malaria. He was then posted to Secunderabad where he fell ill with cholera. It is reported that he was cured by being fed hot tea. When he had recovered, he started work again trying to establish the link between malaria and mosquitoes.

Ross toiled through a series of experiments in the extreme heat of August in India, all of which failed. He wrote to his wife saying:

"I have failed in finding parasites in mosquitoes fed on malaria patients, but perhaps I am not using the proper kind of mosquito".

One of the difficulties Ross faced was that there were many different sorts of mosquitoes and it was possible only one type carried the parasite.

Ross continued; this time with more luck.

On August 16 he wrote to his wife that he had found another type of mosquito for his experiment. These mosquitoes were a type he had not seen before. He called them "dapple-wing", because their wings were covered with little spots or "dapples". Ross then fed the females (only females suck blood), on a man named Husein Khan who was a malaria patient. Husein Khan was paid 1 anna per mosquito he was bitten by; he came away with 10 annas.

On August 17 Ross killed and dissected two of these mosquitoes and found nothing unusual.

On August 19 he killed another and found "some peculiar vacuolated cells in the stomach about 10 microns in diameter"; he paid little attention to them.

The next day, August 20, Ross decided to kill one of the remaining mosquitoes he had fed on Husein Khan. He dissected the tissue, micron by micron and to his surprise he; "saw a clear and almost circular outline too small to be the stomach-cell of an ordinary mosquito. I looked a little further. Here was another and another exactly similar cell". August 20 came to be known as Mosquito Day.

The next day he killed and dissected the remaining specimen and found 21 cells, just the same as the other, but this time larger. The cells were malaria parasites growing in the mosquito tissues. Now Ross needed to find the connection between dapple-wing mosquitoes and people infected with malaria.

On the 4 September he joined his family at Bangladore where he wrote a paper on his findings. This paper was published in the British Medical Journal on December 18 1897. Unfortunately he was posted to Rajputana later that month, where there was little endemic malaria.

Things were to improve in 1898 when he was posted to CALCUTTA (!) where a laboratory was made available to him. While he was in Calcutta, Ross read the work of an American called MacCallum who had identified the Plasmodium parasite in infected birds. Ross decided to follow this line. He took mosquitoes fed on infected birds and fed them on uninfected birds. The uninfected birds became infected.

Reporting back to Manson on the 25 June Ross wrote that he had found "germinal rods", in the stomach lining of the mosquito. By 29 June he had located them in the blood cavity and on the 4 July he found them in the salivary glands. The complicated life cycle of the plasmodium parasite had been uncovered. The parasite bred in the stomach of the female mosquito, travelled through the bloodstream to the salivary glands and was injected into the victim with the saliva when the mosquito bit through the skin.

That month Manson declared Ross's work to the BMA.

In 1899 Ross decided to return to England. Manson had arranged a post for him at the Liverpool School of Tropical Medicine and Ross became their first lecturer in tropical disease. He remained involved with the Liverpool School of Tropical Medicine from 1899 to 1912, during which time he was awarded the Nobel Prize for Medicine and in 1911 received a knightood. By 1912, however, Ross had become so disillusioned with his pay and conditions that he moved to London to improve his situation. While he London he saw the founding of the Ross Institute and Hospital for Tropical Diseases at Putney.

Ross died on 16 September 1932 at the Ross Institute
A simple daily change of routine that took place when I came to live in Kolkata is putting up the mosquito net each and every night: the best prevention against malaria yet.

A friend who visited us from Ireland had a classic line after staying over with us in her net: "let me tell you, the mosquitoes were really surfing my net last night!"