Living with malaria

Living with malariaEveryone in India, at some point in their lives, may have been infected with malaria. Now this may sound a little out there, but may not be something far away from reality. Just recently, Times of India reported that 67 people died in Tripura of malaria in the last month alone, and 55 among them, were children. The north eastern state of our country is amongst one of the most gravely hit regions when it comes to malarial outbreaks, along with the other red zone regions, Andaman and Nicobar islands and Pondicherry. 

Malaria has been around in India for quite a while now. In fact, the discovery of its vector- the mosquito was done here in India by Sir Ronald Ross who bagged the Nobel Prize in Physiology and Medicine for his discovery. There are about 250 million people affected every year with the malarial parasite, out of which nearly 2 million succumb to the disease. In India, alone we face a daunting number of around 30,000- 50,000 deaths caused due to malaria each year, most of them being children. This is very different from what is officially released by the government which is hugely down playing the numbers to a mere 1,023 deaths in 2010 and 440 deaths in 2013. (True number of malarial deaths in India)

But it is not just recently that the malarial parasite has been causing havoc. Estimates are that the malarial parasite, Plasmodium, is the single most deadly organism known to the human race. If numbers are to be believed it has done more damage to humanity that any war, or natural calamity, making it the deadliest parasite ever. Vasco da Gama, Genghis Khan, Alexander the great are just a few names out of the many who succumbed to the malaria.

Since the dawn of humanity itself, malaria, has been at the periphery of our existence. The first documented case of malaria comes from Hippocrates, the father of medicine, who described the symptoms. It is believed that the co-relation that was made between stagnant water and the spread of the malarial disease, prompted the Romans to build the drainage system. But the very fact that the parasite has been around for a while and managed to survive changes in its environment says quite a bit about its evolution, doesn’t it?

Marsh fever
marsh fever

In the past, we had effective drugs to curb the disease, but the parasite soon grew resistant to the drug, which is why even today, we face a threat that malaria might turn into a global pandemic. Arteminisin, has been one of the most effective drug developed against the malarial parasite till date. But recently, cases in Cambodia have surfaced, where in the most deadly of the malarial strain- Plasmodium falcipuram, has shown resistance to the drug. This is not only an interesting development; in terms of evolution, but also in terms of global health, where there can be absolutely no sure shot way we could combat the spread of the disease.

But this is not where the weirdness of the evolution and smartness (if I may add) of the parasite ends. Researchers at the Pennsylvania State University have observed that infection of Plasmodium in hosts that have been exposed to some malarial vaccines before results in the parasite launching a deadlier attack on the host. This is not to say that the parasite comes up with some novel way of attaching the host, it simply multiplies more aggressively, overwhelming the host immune system rendering the vaccine useless. The parasite even manages to modify its vector, the mosquito's behaviour, who show greater affinity for human blood, after being infected by Plasmodium. 

Luckily, the evolutionary adaption is not just one sided. According to a malaria hypothesis, put forth by J. B. S. Haldane in 1949, the prominence of red blood cell disorders, in the tropical regions was an indication of natural selection at work. Red blood cell disorders like sickle cell anaemia and thalassemia discourage the infection of red blood cells. This was later confirmed by A.C. Allison who showed that the mutation in the sickle cell mutation (in the beta hemoglobin gene) was geographically confined to Africa, where malaria is most wide spread. 

But the bottom line remains, that even though we seem to evolve ourselves and our methods to combat malaria, the rate at which the plasmodium is evolving is much faster and we need to come up with a better understanding of the parasite and novel techniques to combat the disease.

For the interested reader, here is an interesting Ted Talk from Prof. Andrew Read on Evolutionary Medicine or why not read our RotM interview with Dr. Justin Boddey from WEHI Australia, who tells us how recent findings in his lab can help us combat malaria successfully

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