Gene-altered mosquitoes to fight malaria

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Researchers at the Malaria Research Institute at Johns Hopkins University in Maryland created genetically modified mosquitoes by giving them a gene that made it impossible for them to pass on the plasmodium parasite that causes malaria. Trials have revealed that the GM mosquitoes could quickly establish themselves in the wild and drive out natural malaria-carrying insects, thereby breaking the route through which humans are infected.

The research, however, is in an early stage, and it may be 10 years before genetically engineered insects are released into the environment.

Contents

Why should I be aware of this?

  • Malaria prevention methods currently followed have not been very successful.
  • There's no vaccine.
  • The pre-exposure prevention treatment and post-exposure medical care are both too expensive for the people most affected by the disease.
  • Till now, the only prevention method that is most effective and yet cheapest to implement is mosquito netting doused in repellant.
  • Gene-based prevention method is a viable and cheap possibility

All about gene-altered mosquitoes to fight malaria

The strategy to fight malaria would require release of tens of thousands of GM organisms into the wild and may be powerful enough to finally bring under control malaria which affects 300 million people a year and causes more than 1 million deaths, mostly of children in sub-Saharan Africa. [1]

Theoretically the strategy of fighting malaria with GM mosquitoes involves creation of a "better," stronger mosquito that will be unable to spread malaria parasites. When tens of thousands of such mosquitoes were released into the wild, they would eventually win the survival game and replace the mosquitoes that are able to spread malaria. In this theoretical solution, once malaria was eradicated from a particular area, it wouldn't come back because the mosquitoes couldn't carry it back.

The research experiment

The research team experimented with equal numbers of genetically modified and ordinary "wild-type" mosquitoes and allowed them to feed on malaria-infected mice. As they reproduced, more of the genetically modified mosquitoes survived. After nine generations, 70% of the insects belonged to the malaria-resistant strain.

The research did demonstrate that transgenic mosquitoes can exhibit a fitness advantage over non-transgenics. The modified mosquitoes had a higher survival rate and laid more eggs. However, when both sets of insects were fed non-infected blood they competed equally well.

The results have important implications as GM mosquitoes that interfered with development of the malaria parasite would make it more difficult for the organism to re-establish themselves once they are eradicated from the area. Malaria is spread by the single-celled parasite Plasmodium.

90 degrees

There exists a great deal of concern about releasing tens of thousands of genetically modified animals into the environment. There’s no way of knowing what would be the long-term effect of this exercise. There are possibilities of widespread ecological implications in which other animal populations might be affected. There is also the likelihood that the malaria parasites might adapt to the genetic makeup of their new hosts, and keep the disease alive but in a form for which we have no treatment at all.

CopperBytes

  • In sub-Saharan Africa, a young child dies of malaria every 30 seconds. [2]
  • Malaria kills more than 1 million people a year. [1]
  • 90% of malaria deaths occur among young children in sub-Saharan Africa. [1]
  • The disease costs Africa $12bn (£6.2bn) in lost GDP and consumes 40% of public health spending. [1]
  • 60% of malaria deaths strike the poorest 20% of the global population. [1]
  • 71% of all deaths from malaria are in the under-fives. [1]
  • Children can die within 48 hours after the first symptoms appear. [1]

Unlearn

There’s, however, an opposing view to the theory. It holds that genetically modifying a mosquito has always appeared to make it weaker. And a weaker, malaria-resistant mosquito won't win the survival game. So, instead of outliving the other variety, it'll just die off.

References:

  • Can genetically modified mosquitoes wipe out malaria?
  • Malaria: GM mosquitoes offer new hope for millions
  • GM mosquito 'could fight malaria'

Source

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Guardian.co.uk
  2. HowStuffWorks