Giving mosquitoes DIET PILLS could combat the spread of malaria, Zika and dengue fever as scientists discover reducing their appetite stops them sucking blood

  • Female mosquitoes suck blood to nourish their developing eggs
  • While she digests, the insect releases proteins that suppress her appetite
  • Giving mosquitoes drugs with these proteins stopped them seeking blood 

By Alexandra Thompson Senior Health Reporter For Mailonline

Published: | Updated:

Although mosquitoes do not need to watch their weight, giving the pests diet pills could combat the spread of malaria, Zika and dengue fever. 

Researchers found the insects given drugs containing NPY-like receptors were less likely to suck blood when they were presented with a human arm. 

These receptors regulate appetite in everything from roundworms to humans, and are even used in experimental anti-obesity medication to curb our desire for food.

Scientists believe if female mosquitoes could be coaxed into receiving these drugs, it may help control deadly diseases with limited treatment options. 

Although mosquitoes do not need to watch their weight, giving the pests diet pills could combat the spread of malaria, Zika and dengue fever, research suggests (stock)

Although mosquitoes do not need to watch their weight, giving the pests diet pills could combat the spread of malaria, Zika and dengue fever, research suggests (stock)

The research was carried out by The Rockefeller University in New York and led by Professor Leslie Vosshall, from the laboratory of neurogenetics and behavior.  

Female mosquitoes suck human blood to help their eggs mature, with each insect having several blood-sucking and egg-laying cycles in her life. 

This means when a female bites a human with a disease like Zika, she has several opportunities to pass that infection on.

WHAT IS ZIKA VIRUS AND HOW IS IT SPREAD?

The Zika virus is spread by mosquito bites, between people during unprotected sex, and from pregnant mothers to their children.

It cannot be cured or prevented with medicines. Although most adults do not become seriously ill from the infection, it can cause serious birth defects if pregnant women get it.

Foetuses' brains can be affected by the virus when it is passed on from the mother and it can cause microcephaly.

Microcephaly is a condition in which babies' heads are unusually small, which can lead to seizures, delayed development and other disabilities.

The virus can also increase the risk of unborn children developing Guillain-Barre syndrome – an uncommon illness in which the immune system attacks the nerves and can cause muscle weakness and paralysis.

Zika is a tropical disease and is most common in Central and South America, Africa and South East Asia.

There was an outbreak of the virus in Brazil's capital, Rio de Janeiro, in 2016 and there were fears that year's Olympic Games would have to be cancelled after more than 200 academics wrote to the World Health Organization warning about it.

The virus is not commonly found in developed countries like the UK, US and Australia. But it is present in the Pacific Islands such as Fiji and Tonga, where the pregnant Duchess of Sussex will visit on her royal tour this month.

Source: Centers for Disease Control and Prevention

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Nearly half the world's population is at risk of malaria, with around 212million cases and 429,000 deaths in 2015 alone, according to the World Health Organization.

And Zika - which is most commonly found in South America but has spread to the US - causes birth defects in around one in ten pregnant women who are infected with the mosquito-spread virus.  

'Preventing mosquitoes from biting humans is an important point of intervention in global public health strategy,' the authors wrote in the journal Cell.

After a female feeds, she stops seeking blood for several days while she allows her eggs to mature. 

Certain peptides - which make up proteins - have been shown to activate NPY-like receptors.

These suppress a mosquito's appetite after she has fed.

NPY-like receptors have also been shown to influence food intake, fullness and obesity in humans. 

To test whether drugs containing these receptors could control mosquitoes, the researchers fed NPY-like receptors to females of the mosquito species Aedes aegypti.

This made the insects less likely to seek out food, as well as bite or suck blood, when exposed to a human arm.  

'When they’re hungry, these mosquitoes are super-motivated,' Professor Vosshall said. 

'They fly toward the scent of a human the same way we might approach a chocolate cake.

'After they were given the drug, they lost interest.' 

NPY-receptors drugs could be administered by drawing mosquitoes into 'baited traps' that mimic the signs of a host the insects are attracted to, such as body odour and carbon dioxide. 

This may be preferable to other techniques that aim to eradicate mosquitoes - even males ones - despite them being important pollinators and food to many fishes. 

Existing control methods, such as insecticides, have limited success due to the insects often developing resistance.   

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