Wednesday, March 28, 2007

War against Malaria: GM as Ammo?

In the war between man and mosquito, malaria claims 2.7 million lives every year. In the scenario where anti malaria drugs become resistant (read outwitted) with unfailing regularity, two different groups of scientists, one working at Johns Hopkins University, Baltimore and the other at Imperial College, London, seem to have transformed the rules of the fight between us and them. They claim that malaria can be fought by releasing into the environment genetically modified mosquitoes that are resistant to the malaria infection. In time, they would wipe out the malaria causing mosquitoes. (Using mosquitoes, to defeat mosquitoes –that had to come from the human brain, didn’t it?) To me, this discovery seems exciting as it seemed to take us out of the vicious cycle of using a drug to treat a disease and then have it become ineffective over a period of time precisely because it is being used. Also, the implication that we could stop using the chemical sprays and the innocuous looking mosquito repellents is worth some optimism. More importantly, once the environment is safer, we do not have to worry about issues like whether a particular drug reaches the underprivileged groups or not. There is also a modicum of thrill — did the researchers ever see that horror flick, Mimic and wonder? But this one is not just silver screen matter but serious science-speak.

Published in the Proceedings of the National Academy of Sciences, the work of the research team at Johns Hopkins vindicates the concept that engineering mosquitoes with cheap lab techniques can help control the killer disease. The idea is that genetically modified mosquitoes can survive in the wild and ultimately completely replace the anopheles mosquito that carries the infection. These enhanced mosquitoes release a protein called SM1 which blocks the malaria parasite from reaching the salivary glands of the mosquitoes which is how the disease is spread in the first place. When the wild and lab designed mosquitoes were fed on Plasmodium infected blood, they showed higher rate of survival.

The actual release of the mosquito into the environment is at least a few years away. Even then, there are some doubts as the experiments have been conducted on mice and with the anopheles stephensi, and not anopheles gambaei which is the main killer in Africa. But my main concern is what environmentalist groups will have to say about replacing a “natural” strain of mosquitoes with a genetically engineered species with red eyes or red testicles. There are serious ecological issues in wiping out traditional mosquitoes that cannot be glossed over. As Jonathan Matthews, editor of GMwatch e-magazine has said, ‘Whatever the initial advantages of GM mosquitoes, their evolutionary sustainability in the longer term is simply an unknown, and this could have a devastating effect on the food chain’ … ‘such a major human intervention could have worryingly unpredictable consequences.’ Conceptually, the unpredictability can be dealt with but strategically, the process itself will be ridden with problems since it involves the release of hundreds and thousands of genetically manufactured mosquitoes into the environment.

Within these polemics and as the GM mosquito is being readied for the wild, localized research continues with great gusto. Undoubtedly dogged by more funding problems than a Johns Hopkins or Imperial College, a group of scientists in India based in IISC, Bangalore, have demonstrated that ‘curcumin’, a component derived from turmeric, in combination with other substances could be developed into a inexpensive, low-toxicity malaria drug. Another group of scientists in Madagascar have isolated a novel compound, tazopsine, from Strychnopsis thouarsii, a plant species found in Madagascar. The characteristics of this compound makes it less likely to become drug resistant.

So war it is – the artillery has been brought out to annihilate the mosquitoes. This lab generated mosquitoes, with their red and green eyes certainly sound like space aliens and stuff of horror films, but I am all for them, if they can garner human victory in the war with the anopheles. I will sleep peacefully sans the hum of the mosquito, sans the toxic fumes of mosquito repellants and gratified to know that the Calcutta chromosome is truly only the stuff of fiction. But most importantly, I will stand by most things that can actually stem the killing of a child every 30 seconds in sub Saharan Africa even if it means denying the ancestors of the ubiquitous mosquito their rightful place under the sun.


D A E said...

'Bringing out the artillery' it is. Reminds me of a saying in Bengali to describe disproportionately over-the-top action: 'mosha martey kamaan daga' (firing a cannon to kill a mosquito). Not as absurd as it sounds at first--you won't find too may mosquitoes on a smoky battlefield, you see. Anyway. What is man's problem with mosquitoes? a) That they suck blood, b) That they spread malaria, dengue and what not. GM mosquitoes don't address a) it seems--so we'll still need repellants for a peaceful night's sleep. As for b), why not modify the malaria parasite so that it self-destructs, rather than create red-eyed mosquitoes that will go out and colonize mosquito populations? Because, I'm yet to see a GM product that wins the survival of the fittest battle. Like they said in Jurassic Park, nature will find a way...

Debjani said...

Dear DAE,
In fact I was thinking of mosha marte kaman daga as I was writing this...
yes, i certainly agree with you that it would be better to come up with lab mosquitoes that would self destruct. There is research in that direction as well but no positive results have come as yet.
Meanwhile GM mosquitoes, if used properly, can be a more thought out response rather than leaving the whole problem of malaria to chance?

ishani said...

It's summer and cooler season again in also the mosquito season. As the heat intensifies so will malaria, dengue and other mosquito related diseases. The Delhi civic authorities are even trying to ban use of the water operated air coolers which have been the mainstay of the entire north Indian plains for many years. That of course would mean more airconditioners and more power for masha marte kaman daga, we have that too in Delhi in the form of fogging by the civic authorities in the lanes and bylanes...not that it helps much though!!!So even though futuristic - GM is the way to go.