Malaria under controlled, hoping same for dengue fever

By Naseem Sheikh

Where mosquito netting and bug spray fail, European scientists are turning to a unique solution to stem the tide of malaria infection worldwide.

Malaria is spread to humans by female mosquitoes who suck blood in order to help their offspring grow, In an effort to slow the spread of malaria, scientists are trying to go to the source — not just by stopping mosquitoes, but stopping how mosquitoes reproduce. Scientists have bred a sperm less male mosquito that could be released into the wild to reduce mosquito populations.

Though there are thousands of mosquito species, only a handful of them can transmit malaria, Entomologist Flaminia Catteruccia says, so targeting these species has the potential to reduce the spread of disease and is less likely to negatively impact the local ecosystem.

Entomologist Flaminia Catteruccia from Imperial College London enlisted the help of her graduate student Janis Thailayil in the search for how to make male mosquitoes sterile but leave them otherwise unharmed.
Mr Thailayil injected 10,000 mosquito embryos with tiny fragments of RNA designed to turn off a gene – called zpg – that is essential for normal sperm development. He do so by injecting a special protein into mosquitoes egg that disturbed the development of male testes but giving no harm or change to other behavioural and sexual functions

Dr Catteruccia explains that female mosquitoes mate only once in their lives. If scientists can trick them into thinking that they have successfully mated, then they will continue to lay their eggs without knowing that they have not been fertilised.

Observing their mating processes in a lab, they found that the males still produced seminal fluid and the females mated with them as usual.

The females acted just the way they do in normal circumstances, eating a blood meal after mating and laying a batch of eggs. They did not seek out a second mating attempt even though their eggs produced no offspring.

Malaria claimed 781,000 lives in 2009, according to the UN’s World Health Organization (WHO), which is heading efforts to distribute insecticide-treated mosquito nets and to spray reproduction sites. Malaria kills around one million people worldwide every year, and in Africa alone, accounts for 20% of all childhood deaths, if it continues unchecked and uncontrolled then more than 225 million people worldwide might suffer from malaria. Each year, nearly 800,000 people will die from disease, according to data from WHO.

In 2009, Australian researchers used modified bacteria to cut the lifespan of mosquitoes in half. Researchers hoped this would reduce the extent to which the bugs spread Dengue fever, an infection that afflicts tens of millions of people each year and kills 20,000.

In 2010, between 2,000 and 3,000 of these short-lived mosquitos were released into the environment in Malaysia as a trial run for reducing Dengue fever rates.

The hope with these various methods is that disease rates (both malaria and dengue as both caused by mosquitoes) can be lowered without negatively impacting the environment.

Naseemshikh@yahoo.com

The article is contributed to pkarticleshub.com