Malaria – a life-threatening disease that blights the lives of million in mostly developing economies – affected 216 million people in 91 countries in 2016, killing 445,000.

The illness, caused by parasites spread by infected female Anopheles mosquitoes, most frequently occurs in countries with poor infrastructure, sparse health facilities and far-flung communities.

Warm, dry weather mixed with rainy downpours that leave dirty water in puddles, lakes and rivers provide the perfect mosquito breeding ground.

The females spread plasmodium parasites, most commonly P. falciparum – responsible for most malaria-related deaths globally – and P. vivax, the main malaria parasite outside sub-Saharan Africa.

The Africa region suffered 90% of infections and 91% of deaths, while malaria causes adds economic to personal tragedy.

The US Centers for Disease Control and Prevention in 2016 estimated the direct costs of the disease in affected countries to be $12 billion while the loss of economic growth is much higher.

Low-tech, and low-cost, responses

Treatments and preventative measures range from bed nets to insecticide sprays, but though scientists hope high-tech developments – such as genetically modified mosquitoes that cannot spread disease – may one day spell malaria’s end, these are still some years away.

But in the meantime, researchers are experimenting with other methods – some of them not so sophisticated – that may yield effective results.

The scent of death

Mimicking the odour of human beings is one way in which researchers may lure the insects to their doom

ISCA Technologies, based in California, United States, is developed inexpensive methods to do just this using called semiochemicals – pheromones or other secretions. These attract insects and could, for example, be poured on to medicated animal herds, which the mosquitoes will target instead of humans injected with chemicals that kill the insects.

ISCA has been conducting trials in Tanzania, Brazil and the US, and the techniques may one day also help fight other diseases, including dengue, West Nile virus and Zika.

Other ISCA ideas include spraying breeding grounds before it rains so chemicals, activated by water, lure females to lay eggs in areas treated with a bacteria that kills the larvae but not other minibeasts.

It also has a plant-based product that smells like nectar and is laced with insecticide. This could be sprayed on outside houses to lure the insects to their deaths.

As well as being inexpensive compared to other measures, ISCA said this allows for more targeted use of insecticides, which would help reduce insect resistance.

Habitat manipulation

A sugar-rich diet is essential for mosquitoes, and invasive plant species can have a direct influence on malaria transmission.

One critical plant is Prosopis juliflora, a variety of mesquite, introduced to the continent in the 1970s to “green” deserts.

In 2016, researchers targeted nine villages in Mali, West Africa, to see if removing the plant affected mosquito numbers. Six of the villages had Prosopis juliflora, three did not.

Flowering branches were removed in three villages and the insect populations monitored in all of them. Those where the branches were removed had a threefold drop in older, more dangerous, Anopheles females and the overall insect number fell by 69.4%.

Villages with the plant, meanwhile, had six times more older females but, as soon as the flowering branches were removed, there was a threefold decrease of mosquitoes here too.

Another new hope?

In August, the Financial Times reported that the first new malaria drug to be developed in 20 years will start clinical trials in Africa and Asia.

The drug, KAF156, is being developed by Swiss drug-maker Novartis with Medicines for Malaria Venture (MMV), a public-private partnership, and charities including Wellcome and Gates Foundation.

Research suggests the medicine quickly clears malaria infection, including resistant strains, and blocks disease transmission. About 500 adults and children with malaria will take part in the trial over the next couple of years in two Asian and seven African countries.

The cost keeps rising

The FT article highlighted one important feature of the global fight against malaria. MMV’s chief executive David Reddy said KAF156 has been developed thanks to a combination of business and philanthropy. “If a company is looking only at a commercial return they are not going to be part of this.”

The poor of developing nations do not have disposable incomes to underpin future drug development.

According to the World Health Organization, total funding for malaria control and elimination cost about $2.7 billion in 2016, with contributions from endemic countries representing $800 million, or 31%.

Fighting the disease is always likely to require a mixture of approaches unless, or until, a single answer can be found.

However, governments around the world considering cutting aid budgets in response to deficits at home risk undermining the progress that has been made so far: increased prevention and control measures have led to a 29% reduction in malaria mortality rates since 2010.

And, as climate change and global travel alter how diseases spread, malaria and illnesses like Zika are appearing in places where they were little known.

“Charity begins abroad” could be a useful motto for countries looking to limit future damage from a killer – but easily stoppable – plague.