Malaria is a familiar foe to every family in the affected countries of sub-Saharan Africa.
Mothers holding small, listless-eyed babies with fever queue outside hospitals and clinics from sunrise in the malarial regions of Nigeria, Uganda or Kenya.
Every year there are more than 200-million cases and about 660 000 deaths – mostly of babies and children under five.
In the decade from 2000 to 2010, the death toll was cut by 26% around the world (33% in Africa) and considerable time, money and effort has been invested in an ambitious bid to eradicate it, but the disease remains a huge threat to life and to surviving children's long-term health and development.
A vaccine could potentially be a game-changer.
The six worst-affected countries are Nigeria, Democratic Republic of the Congo, Tanzania, Uganda, Mozambique and Côte d'Ivoire, which have 47% of the world's cases: 103-million.
India, with 24-million cases a year, has the highest burden in south-east Asia.
Malaria is caused by the bites of a mosquito – usually a female Anopheles mosquito – carrying the malaria parasite, which then makes its way through the blood stream to the liver, where it matures and reproduces.
The symptoms include fever, headache, chills and vomiting and can progress to coma and death.
Small children and pregnant women are most susceptible.
Because the mosquitoes bite between dusk and dawn, insecticide-impregnated nets have been widely distributed to households in a massive campaign pushed by the United Nations.
But surveys have shown that they are not always primarily used by children.
A report by the National Audit Office in July said the UK had paid for 25-million nets since 2010, but in four countries where they had been distributed – Sierra Leone, Tanzania, Nigeria and Burma – while 23% more families owned nets, the increase in children sleeping under them has only been 11.6%.
The number of nets distributed has declined, according to the World Malaria Report from the United Nations in 2012.
In 2010, 145-million nets were delivered to sub-Saharan Africa, but only an estimated 66-million were dispatched in 2012.
That, said the World Health Organisation (WHO), is not enough to replace nets that are no longer effective – through holes or the insecticide wearing off – from three years earlier.
The WHO says 150-million new nets are needed every year. Indoor insecticide spraying is also being used, but only for 5% of the population at risk, the WHO says.
A new class of drugs has brought high hopes of reducing the risk of catching malaria.
?Artemisinin combination therapies, combining drugs made from the artemisinin plant – originally grown and used in China – with older drugs have high efficacy.
The new therapies have been introduced rapidly to sub-Saharan countries where the malaria parasite has become resistant to older drugs such as chloroquine and sulfadoxine pyrimethamine.
In 2011, 278-million courses of the artemisinin combination drugs were bought for use in endemic countries. But there are fears that resistance may undermine these new drugs too. It has already been seen in four countries: Cambodia, Myanmar, Thailand and Vietnam.
Travellers to malarial regions usually take prophylactic drugs, like GlaxoSmithKline's once-daily Malarone tablets or Roche's Lariam, which is intended for longer term use (up to one year).
The US Food and Drug Administration now warns that Lariam can cause serious neurological and psychiatric side-effects.
No such drugs have been developed to prevent malaria in the small children born in malarial regions.
Few people think they would be an option.
But even a partially effective vaccine, in addition to the nets, spraying and treatments now available, could make a real difference, experts believe. – guardian.co.uk © Guardian News and Media 2013