By Matt McGrath
Science reporter, BBC World Service



Malaria-carrying mosquitoes are disappearing in some parts of Africa, but scientists are unsure as to why.

Figures indicate controls such as anti-mosquito bed nets are having a significant impact on the incidence of malaria in some sub-Saharan countries.

But in Malaria Journal, researchers say mosquitoes are also disappearing from areas with few controls.

They are uncertain if mosquitoes are being eradicated or whether they will return with renewed vigour.

Data from countries such as Tanzania, Eritrea, Rwanda, Kenya and Zambia all indicate that the incidence of malaria is dropping fast.

Researchers believe this is due to effective implementation of control programmes, especially the deployment of bed nets treated with insecticide.

But a team of Danish and Tanzanian scientists say this is not the whole story. For more than 10 years they have been collecting and counting the number of mosquitoes caught in thousands of traps in Tanzania.

In 2004 they caught over 5,000 insects. In 2009 that had dropped to just 14.

More importantly, these collections took place in villages that weren't using bed nets.

'Chaotic rainfall'
One possibility for the reduction in numbers is climate change. Patterns of rainfall in these years were more chaotic in these regions of Tanzania and often fell outside the rainy season. The scientists say this may have disturbed the natural cycle of mosquito development.

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It is most likely we will have an epidemic of malaria ”

Professor Dan Meyrowitsch,
University of Copenhagen
But the lead author of the study, Professor Dan Meyrowitsch from the University of Copenhagen, says that he is not convinced that it is just the changing climate.

"It could be partly due to this chaotic rainfall, but personally I don't think it can explain such a dramatic decline in mosquitoes, to the extent we can say that the malaria mosquitoes are almost eradicated in these communities.

"What we should consider is that there may be a disease among the mosquitoes, a fungi or a virus, or they're may have been some environmental changes in the communities that have resulted in a drop in the number of mosquitoes"

The research team also found anecdotal evidence that their discovery was not an isolated case.

Prof Meyrowitsch added: "Other scientists are saying they can't test their drugs because there are no children left with malaria.

"They observed this in communities with no large interventions against malaria or mosquitoes. It may be the same scenario that the specific mosquitoes that carry malaria are declining very fast now"

The researchers are unsure if mosquitoes will return to these regions. If they do, one particular cause for concern is the young people who have not been exposed to malaria over the past five or six years since the mosquitoes began to decline.

"If the mosquito population starts coming up again" says Professor Meyrowitsch "and my own assumption is that it will, it is most likely we will have an epidemic of malaria with a higher level of disease and mortality especially amongst these children who have not been exposed."


http://www.bbc.co.uk/news/health-14685612

Recently in Lagos, I've been plastering my window nets with dead mosquitoes at an increasing rate. I wonder what the stats indicate for Nigeria.

Mosquito self get sense na . . .

No market for africa again

Thay have been migrating to Europe and North America just like all other creatures, smart blood-suckers.

Bet naija mosquitoes are not part of the statistics.

Any time you spray insecticide, Naija mosquitoes will just "hold their nose" and wait at the door. Once the insecticide effect has died down and you open the door, they simply follow you in and teach you a lesson.

Sorry d mosquitoes r on STRIKE n demandin New Maximum Quantity of blood since we don de hide our blood de form Slimness n washin of Weight, dont worry soon dm go start civil War by November December

190smh:

I heard in NIGERIA

People upload dead mosquitos on facebook

so when the live ones browse their profiles they simply evade that house

how true is it 

looool

If it is because of climate change they better adapt fast fast oo or should they? Hmm. .
If they are migrating to Europe mek I pack my bag migrate back to Africa. Maybe, soon African will become First World. .It's the mosquitos' fault

Recent studies has told us there has been a drop but statistical figures among human has shown that Blood deficiency disease as been on †ђε̲̣ steady rise disease such as Aids,Hepatitis B and it was even discovered that most Nigerians Blood contains Harmful substances τ̲̅ȍ Mosquito such as Alomo,Asianma,Monkey tail plus average nigerians aя̩̥̊ε̲̣̣̣̥ underfed all of which causes Havoc τ̲̅ȍ them when Sucked because ​ђã†̥ good Ȋ̝̊̅§ i̶̲̥̅̊n̶̲̥̅̊ drinking a Hungry man's Blood .I̶̲̥̅̊n̶̲̥̅̊ my opinion ℓ̊ want τ̲̅ȍ belief they Migrated τ̲̅ȍ where †ђε̲̣ Bloods aя̩̥̊ε̲̣̣̣̥ safer and more nourished.wait sef!where Ȋ̝̊̅§ this poster getting his statistics from, Na amnesty I do with them before they Let M̶̲̅ε̲̣ live i̶̲̥̅̊n̶̲̥̅̊ peace om, Na amnesty I do with them before they Let M̶̲̅ε̲̣ live i̶̲̥̅̊n̶̲̥̅̊ peace

AIDS dey catch Mosqy too?

owobokiri:

AIDS dey catch Mosqy too?

looooooool

Look @ it from dz angle,when last you hear say winch suck person blood? Its simply because †ђε̲̣ bloods aя̩̥̊ε̲̣̣̣̥ not safer anymore,

Ahahahaha

Our blood don dey bitter.

I dey suspect cell phone mast radiation

phuck_NL:

Bet naija mosquitoes are not part of the statistics.

Any time you spray insecticide, Naija mosquitoes will just "hold their nose" and wait at the door. Once the insecticide effect has died down and you open the door, they simply follow you in and teach you a lesson.

This is very funny.

Naija mosquitoes are evolving into things like houseflies and roaches; they can't be called mosquitoes anymore, so I guess the report is true.

mosquitoes hate corruption with perfect hatred,that is why they are moving out of africa.

the mosquitoes are fasting. they ll b back after the sallah

Hunger in africa is just 2much! Dey cnt eat anythn 4m Africa again

they are increasing in my area ooo

Good riddance. They have sucked enough African blood.
I hate mozziessss

no wonder mosquitoes plenty for my area,so dem don dey migrate from other african country come to nigeria where awuf dey berekete.

Hmmnn, Have they checked for any recent Chinese influx? The last time dogs were disappearing from African cities and villages, they were traced to dinner plates in nearby Chinese settlements.

Mosquitoes when i dey fight with everyday for house

The answer is simple, dis scientist sef them no no anything,
The UN of Mosquitos across the globe are holding a meeting at the amazon forest to improvise on gas masks,tolerance to any kind of toxic blood,plans to invade america and europe cos my ppl even mosquitos noticed d d level of hunger and economic meltdown in africa

They could be relocating to Nigeria and other countries with low sanitary conditions or possibly mutating into something else.

symbianDON:

the mosquitoes are fasting. they ll b back after the sallah

guys, teh Credit crunch affact thier global market lol

quinne25:

Hunger in africa is just 2much! Dey cnt eat anythn 4m Africa again

lol.