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."

VIDEO
News
Strange 'quack' noises could be undersea chatter of Minke whales
science
Voices
voices Furore is yet another example of shameful Westminster evasion, says Nigel Farage
News
weird news... and film it, obviously
Arts & Entertainment
tv
Sport
sport
News
Matthew Mcnulty and Jessica Brown Findlay in 'Jamaica Inn'
mediaHundreds complain over dialogue levels in period drama
News
peopleJay Z and Beyoncé to buy £5.5m London townhouse
Voices
voicesMoyes' tragedy is one the Deputy PM understands all too well, says Matthew Norman
Arts & Entertainment
Rocker of ages: Chuck Berry
musicWhy do musicians play into old age?
News
Jilly's jewels: gardener Alan Titchmarsh
peopleCountry Life magazine's list of 'gallant' public figures throws light on what it means to be a gentleman in the modern world
Sport
John Terry goes down injured in the 70th minute
sportAtletico Madrid 0 Chelsea 0: Blues can finish the job at Stamford Bridge, but injuries to Terry and Cech are a concern for Mourinho
Student
student
News
<b>Rebecca Adlington</b>
<br />This, the first British swimmer to win two
Olympic gold medals in 100 years, is the eversmiling
face of the athletes who will, we're
confident, make us all proud at London 2012
peopleRebecca Adlington on 'nose surgery'
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
Have you tried new the Independent Digital Edition iPad app?
Independent Dating
and  

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

iJobs Job Widget
iJobs General

Brand Manager, Bermondsey

£32000 - £35000 per annum: Charter Selection: This highly successful organisat...

International Brand Manager, Slough

£40000 - £45000 per annum, Benefits: Bonus: Charter Selection: This rapidly ex...

English Teacher

£450 - £750 per annum: Randstad Education Leicester: English teacher required ...

Humanities Teacher

£90 - £160 per day: Randstad Education Leicester: Randstad Education is curren...

Day In a Page

Brits who migrate to Costa del Sol more unhappy than those who stay at home

It's not always fun in the sun: Moving abroad does not guarantee happiness

Brits who migrate to Costa del Sol more unhappy than those who stay at home
Migrants in Britain a decade on: They came, they worked, they stayed in Lincolnshire

Migrants in Britain a decade on

They came, they worked, they stayed in Lincolnshire
Chris Addison on swapping politics for pillow talk

Chris Addison on swapping politics for pillow talk

The 'Thick of It' favourite thinks the romcom is an 'awful genre'. So why is he happy with a starring role in Sky Living's new Lake District-set series 'Trying Again'?
Why musicians play into their old age

Why musicians play into their old age

Nick Hasted looks at how they are driven by a burning desire to keep on entertaining fans despite risking ridicule
How can you tell a gentleman?

How can you tell a gentleman?

A list of public figures with gallant attributes by Country Life magazine throws a fascinating light on what it means to be a gentleman in the modern world
Pet a porter: posh pet pampering

Pet a porter: posh pet pampering

The duo behind Asos and Achica have launched a new venture offering haute couture to help make furry companions fashionable
A History of the First World War in 100 moments: The mutiny that sent a ripple of fear through the Empire

A History of the First World War in 100 moments

The mutiny that sent a ripple of fear through the Empire
Hot stuff: 10 best kettles

Hot stuff: 10 best kettles

Celebrate St George’s Day with a nice cup of tea. Now you just need to get the water boiled
Sam Wallace: Why Giggs is perfect fit as Manchester United boss... in the longer term

Sam Wallace

Why Ryan Giggs is perfect fit as Manchester United boss... in the longer term
Renaud Lavillenie: The sky's the limit for this pole vaulter's ambitions

Renaud Lavillenie: The sky's the limit for this pole vaulter's ambitions

Having smashed Sergei Bubka's 21-year-old record, the French phenomenon tells Simon Turnbull he can go higher
Through the screen: British Pathé opens its archives

Through the screen

British Pathé opens its archives
The man behind the papier mâché mask

Frank Sidebottom

The man behind the papier mâché mask
Chris Marker: Mystic film-maker with a Midas touch

Mystic film-maker with a Midas touch

Chris Marker retrospective is a revelation
Boston runs again: Thousands take to the streets for marathon as city honours dead and injured of last year's bombing

Boston runs again

Thousands of runners take to the streets as city honours dead of last year
40 years of fostering and still holding the babies (and with no plans to retire)

40 years of fostering and holding the babies

In their seventies and still working as specialist foster parents