Grace Mwende pikin dem dey sleep under mosquito net wey dem spray wit insecticide every night, but malaria still dey catch dem.

Dis na wahala wey no be only Grace, wey be mama of three for Kilifi County, Kenya, dey face. E dey affect millions of families for Africa wey malaria dey worry.

Di main problem na say di Anopheles mosquito wey dey spread di disease don sabi change di way dem dey behave.

Before-before, dem dey bite for night, but now dem don start dey bite for daytime too, even when pikin dem dey play for house, where mosquito net no fit protect dem.

But new technology wey di World Health Organisation (WHO) don approve fit help mama dem like Grace rest small.

Dem dey call di device 'spatial emanators'. E dey release chemical wey go drive mosquito comot for house air, so e fit protect people anytime, day or night.

Grace talk say, "If dis thing fit stop mosquito when we no dey under net, e go change everything. Malaria dey spoil our pikin health and dey chop di money wey we for use do better thing. We need all di help we fit get."

Malaria dey kill almost 600,000 people every year for Africa, and na pikin wey never reach five years old dey die pass.

Even though mosquito net and spray don save plenty lives, mosquito dem don dey wise. Dem don dey resist di insecticide and don change di time wey dem dey bite.

Di spatial emanators fit help close di gap. Di device dey release chemical like transfluthrin wey go confuse, drive or even kill mosquito.

Unlike mosquito net wey dey protect only di person wey dey under am, di emanators dey protect di whole house.

Dr Samuel Bangura, wey be public health specialist for Sierra Leone, talk say, "We don see how net dey save life, but mosquito dey adapt. If dis emanators fit protect people even when dem dey cook or study for house, malaria case fit reduce well-well."

WHO don approve two spatial emanator products – Mosquito Shield wey dey last for one month, and Guardian wey fit work for one year.

Dis approval mean say government and aid organisations fit start to distribute dem for plenty places.

Research wey Unitaid fund don show say di technology fit reduce malaria transmission by 30% if dem use am with mosquito net.

Dr Philippe Duneton from Unitaid talk say, "Dis na di first new tool for vector control wey we don see for many years. We gatz make sure say di people wey need am pass fit get am."

Scientists still dey do research to know whether di emanators go work well without mosquito net and if e fit protect people for outside or refugee camp.

Dem also dey check whether mosquito go later sabi resist di chemical wey di emanators dey release.

Early trials for Peru show say di emanators fit reduce dengue infection. Another study for Southeast Asia dey under review.

If di trials succeed, di emanators fit become tool wey go help fight different mosquito diseases for tropical areas.

For African families wey dey suffer mosquito wahala, di emanators no be just science. E mean say pikin go dey healthier, dem go spend less for hospital, and pikin no go dey miss school anyhow.

Grace talk for plenty mama dem when she say, "If dis thing work, e go be like shield wey dey protect our house."