Malaria fears escalate as most dangerous mosquito mutates into two species

Most dangerous mosquito is evolving to create a new problem for Africa, and for scientists fighting disease

The most dangerous type of malaria-carrying mosquito, which kills up to a million people each year, is evolving into two different species, posing grave problems for controlling the transmission of the blood parasite.

Scientists have found that Anopheles gambiae, which is widespread across Africa and is responsible for about half of the 500 million new cases of malaria each year, has split into two genetically different strains that are well on their way to becoming distinct species.

The revelation could present real difficulties in controlling malaria because eradication strategies directed against one mosquito species may not be effective against another, according to the scientists who discovered the genetic differences between the two strains.

"From our new studies, we can see that mosquitoes are evolving more quickly than we thought and that unfortunately strategies that might work against one strain of mosquito might not be effective against another," said Mara Lawniczak of Imperial College London.

"Our studies help us to understand the makeup of the mosquitoes that transmit malaria, so that we can find new ways of preventing them from infecting people," said Dr Lawniczak, the lead author of one of the two studies published in the journal Science.

Malaria is caused by a microscopic blood parasite that is transmitted in the bite of female mosquitoes, which need a blood meal to produce their eggs. Out of the 500 million people who become infected with malaria following a mosquito bite each year, some two million die of the disease.

Anopheles gambiae is one of many dozens of mosquito species capable of transmitting malaria, but it is considered one of the worst culprits because it is so widespread across Africa.

It was known for some time that Anopheles gambiae consisted of two strains, known as M and S, but Dr Lawniczak said the full extent of the genetic differences between these two subpopulations had only emerged from full genome scans of their DNA.

"This Anopheles mosquito has always been thought of as one species and even though we knew they were diversifying and hybridising we didn't think it had got this far along the path to become two distinct species," she said.

"You really cannot tell by looking at them that they are so different genetically. Yet we have to know that any efforts directed at controlling mosquitoes will work in all the different groups that transmit malaria. A strategy that works in one group may not end up working in another."

Previous research had suggested that the differences in the DNA of each strain were concentrated on only parts of the insect's chromosomes. However, the latest studies found that significant differences could be found scattered throughout the genomes.

"We were surprised to find out just how different the two strains are genetically. We had thought that the differences were only going to be in defined areas of the chromosome but in fact we found differences all over the genome," Dr Lawniczak said.

It is likely that the "S" strain is the ancestral species because it is found all over sub-Saharan Africa, whereas the "M" strain is concentrated on central and west Africa. The "M" strain also appears to have become better adapted to laying its eggs in rice paddies, which are a relatively recent introduction to the continent.

Professor George Christophides, also of Imperial College, said the genetic studies into Anopheles gambiae demonstrated just how fast the species was evolving, underlining the importance of monitoring future changes in order to keep track of the most dangerous carrier of malaria.

"Malaria is a deadly disease that affects millions of people, and amongst children in Africa it causes one in every five deaths," Professor Christophides said. "The best way to reduce the number of people who contract malaria is to control the mosquitoes that carry the disease.

"Our studies help us to understand the makeup of the mosquitoes that transmit malaria, so that we can find new ways of preventing them from infecting people."

PROMOTED VIDEO
News
ebookA unique anthology of reporting and analysis of a crucial period of history
Life and Style
Phillips Idowu, Stella McCartney and Jessica Ennis
fashionMcCartney to continue designing Team GB Olympics kit until 2016
Sport
Shinji Kagawa and Reece James celebrate after the latter scores in Manchester United's 7-0 victory over LA Galaxy
football
Voices
voicesGood for Lana Del Rey for helping kill that myth, writes Grace Dent
Sport
Farah returns to the track with something to prove
Commonwealth games
Life and Style
fashion Designs are part of feminist art project by a British student
Independent
Travel Shop
the manor
Up to 70% off luxury travel
on city breaks Find out more
santorini
Up to 70% off luxury travel
on chic beach resorts Find out more
sardina foodie
Up to 70% off luxury travel
on country retreats Find out more
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

SQL Report Analyst (SSRS, CA, SQL 2012)

£30000 - £38500 Per Annum + 25 days holiday, pension, subsidised restaurant: C...

Application Support Analyst (SQL, Incident Management, SLAs)

£34000 - £37000 Per Annum + excellent benefits: Clearwater People Solutions Lt...

Embedded Software / Firmware Engineer

£40000 - £45000 per annum + Pension, Holiday, Flexi-time: Progressive Recruitm...

Developer - WinForms, C#

£280 - £320 per day: Progressive Recruitment: C#, WinForms, Desktop Developmen...

Day In a Page

Screwing your way to the top? Good for Lana Del Rey for helping kill that myth

Screwing your way to the top?

Good for Lana Del Rey for helping kill that myth, says Grace Dent
Will the young Britons fighting in Syria be allowed to return home and resume their lives?

Will Britons fighting in Syria be able to resume their lives?

Tony Blair's Terrorism Act 2006 has made it an offence to take part in military action abroad with a "political, ideological, religious or racial motive"
Beyoncé poses as Rosie the Riveter, the wartime poster girl who became a feminist pin-up

Beyoncé poses as Rosie the Riveter

The wartime poster girl became the ultimate American symbol of female empowerment
The quest to find the perfect pair of earphones: Are custom, 3D printed earbuds the solution?

The quest to find the perfect pair of earphones

Earphones don't fit properly, offer mediocre audio quality and can even be painful. So the quest to design the perfect pair is music to Seth Stevenson's ears
US Army's shooting star: Lt-Col Steven Cole is the man Hollywood calls when it wants to borrow a tank or check a military uniform

Meet the US Army's shooting star

Lt-Col Steven Cole is the man Hollywood calls when it wants to borrow a tank or check a military uniform
Climate change threatens to make the antarctic fur seal extinct

Take a good look while you can

How climate change could wipe out this seal
Should emergency hospital weddings be made easier for the terminally ill?

Farewell, my lovely

Should emergency hospital weddings be made easier?
Man Booker Prize 2014 longlist: Crowdfunded novel nominated for first time

Crowdfunded novel nominated for Booker Prize

Paul Kingsnorth's 'The Wake' is in contention for the prestigious award
Vladimir Putin employs a full-time food taster to ensure his meals aren't poisoned

Vladimir Putin employs a full-time food taster

John Walsh salutes those brave souls who have, throughout history, put their knives on the line
Tour de France effect brings Hollywood blockbusters to Yorkshire

Tour de France effect brings Hollywood blockbusters to Yorkshire

A $25m thriller starring Sam Worthington to be made in God's Own Country
Will The Minerva Project - the first 'elite' American university to be launched in a century - change the face of higher learning?

Will The Minerva Project change the face of higher learning?

The university has no lecture halls, no debating societies, no sports teams and no fraternities. Instead, the 33 students who have made the cut at Minerva, will travel the world and change the face of higher learning
The 10 best pedicure products

Feet treat: 10 best pedicure products

Bags packed and all prepped for holidays, but feet in a state? Get them flip-flop-ready with our pick of the items for a DIY treatment
Commonwealth Games 2014: Great Scots! Planes and pipers welcome in Glasgow's Games

Commonwealth Games 2014

Great Scots! Planes and pipers welcome in Glasgow's Games
Jack Pitt-Brooke: Manchester City and Patrick Vieira make the right stand on racism

Jack Pitt-Brooke

Manchester City and Patrick Vieira make the right stand on racism
How Terry Newton tragedy made iron men seek help to tackle their psychological demons

How Newton tragedy made iron men seek help to tackle their psychological demons

Over a hundred rugby league players have contacted clinic to deal with mental challenges of game