Parasite hunters bag this year’s Nobel Prize
Parasites, inhabitants of the earth, living side by side with humans, animals and plants are a special group of organisms that have evolved a seemingly carefree life style receiving shelter and food from other living beings. Therefore we can classify parasites as those that derive shelter and sustenance from another. This ‘the other’ being victimized or plundered. Looking at our societies we can classify some human beings also as parasites because they satisfy our definition. Although their lifestyles appear carefree specially the human kind, the life of a parasite that affects human beings is far from simple and to get into the slot of being an elite and efficient parasite it had to evolve for over thousands of years in different hostile environs.
A child is given an injection as part of a malaria vaccine trial at a clinic in the Kenya coastal town of Kilifi. (Reuters)
Parasites have taken shelter in the human body from time immemorial and they or their life stages have been recovered from mummies of great antiquity. Parasites fall into a group that is so different to bacteria, fungi and viruses. Although many are single celled organisms like the malaria parasite, quite a number are comparatively larger organisms like the worms that infect humans.
Plundering the human body these tiny single celled parasites or their larger counterparts like the worms, have caused havoc and devastations in the afflicted and have been responsible for decimation of civilizations and hazardous geographical readjustments. In this respect some historians believe that the fall of the Rajarata civilization and the subsequent shift of kingdoms to the southern parts of the isle of Lanka were due to or following malaria epidemics. The destruction of the intricate irrigation system of the Rajarata civilization following repeated Chola and Pandayan invasions may have resulted in prolific breeding of the Anopheles mosquitoes that transmit malaria – the mosquito being endemic in the dry zone. Similar historical sentiments have been cited regarding the fall of the Roman empire following widespread malaria in and around the marshes of Rome and Pompeii.
Looking at recent history one can see the devastation caused by comparatively larger parasites like worms particularly in Sub-Saharan Africa leading to abandoning of fertile land in desperate efforts to flee from endemic locations. This is very true of the parasitic infection commonly known as ‘River Blindness’ , caused by a skin invading filarial worm whose young stages of the life cycle affect the eye leading to blindness. Similarly lymphatic filariasis known to Sri Lankans as “barawa’, is caused by another filarial worm that lives in the lymphatic system of the human body. This infection is responsible for severe disfigurement and swelling of limbs and genitals stigmatizing the affected socially. These parasitic infections together affect more than 100 million people in Sub-Saharan Africa, South Asia and South and Central America.
Many Sri Lankans, particularly of our vintage have heard the success story of the Malaria eradication programme. They also would know how the post eradication surveillance lapsed and how malaria re-emerged with a vengeance. Tremendous sacrifices have been made by anti-malaria workers and hopefully we see the end of the tunnel and our dream now is to eliminate the scourge from our shores by 2010. But being an island we remain vulnerable to imported malaria in this era of rapid transportation and vigorous tourist promotional programmes.
Historically when humans saw that they were harboring parasites such as worms remedial measures were taken mostly in the form of plant and mineral materials. Over centuries new findings in the battle against the parasites gave us temporary respite but the hiding enemy always won. Humans have conquered many a marvel that was unthinkable a century ago like the moon landing but succumb pitifully to tiny parasites that refuse to vacate the human body.
The Nobel Prize for Physiology or Medicine this year was triumphantly won by three scientists whose discoveries led to alleviate suffering and misery of millions of people afflicted with parasitic infections living in the poorest regions of the modern world. We who are involved in parasitic infections and teach and train countless medical undergraduates and postgraduates salute these three scientists who relentlessly pursued their research in the face of failures, defeats and ultimate triumph.
This year’s prize was shared between the three scientists; the two who developed an effective, easily available, low cost drug with minimal side effects against parasites causing river blindness and lymphatic filariasis together received one half of the prize. The other half was awarded to a lady scientist who researched on traditional Chinese medicine that led to the discovery of the current panacea against multi drug resistant malaria.
Santoshi Ômara, one of the duo that shared the prize, is a Japanese scientist born in 1935. His work involved countless cultures of soil inhabiting bacteria – a species of Streptomyces that produce an active compound with potent antiparasitic activity. He received his doctoral degree in 1968 from the University of Tokyo. Currently he is with the Kitasato University as Emeritus Professor.
William C. Campbell was born in Ireland in 1930. He received his first degree from Trinity College, University of Dublin in 1952. His doctoral degree is from the University of Wisconsin (1957). Following a long stint with the Merck Institute for Therapeutic Research, he took up the position of Fellow Emeritus at Drew University, New Jersey, USA. Campbell took up the material produced by Santoshi Omara, and carried out experiments in animals and then in humans, ultimately leading to the production of Ivermectin from Avermectin. Ivermectin has brought hope to millions of people affected by river blindness and lymphatic filariasis. The Nobel committee very fittingly felicitated these two men who will be remembered by grateful humans across the world.
Chinese scientist Youyou Yu (born in 1930) graduated in 1955 from the University of Beijing. Delving into the treasure trove of Chinese medicine, at a time when drug resistant malaria was spreading like wildfire she unearthed the wonder plant –Artemisi annua , a relative of our native ‘Wal Kolondu” that would yield a potent component that is able to kill the malaria parasite. Thus, the drug Artemisin was born. She shares the prestigious prize.
We are very happy indeed that this year’s Nobel Prize for Physiology or Medicine has been awarded to three dedicated scientists associated with Parasitology whose lifelong efforts led to alleviating suffering and misery of millions of afflicted people in the poorest areas of the world today.