Lifesavers · No. 07

Insecticide-treated bed nets

A treated mesh net over a bed turned out to be the single biggest reason malaria retreated across Africa, behind most of an estimated 663 million cases averted.

68% of 663 million cases lives — share of an estimated 663 million clinical malaria cases averted in Africa since 2000 attributable to bed nets

Measured in cases averted rather than deaths, from Bhatt et al., Nature, 2015.

Credited to
Bed nets are ancient; treating them with long-lasting insecticide and distributing them at scale was developed and rolled out from the 1980s to the 2000s.
When
1980s onward

How it saves lives

Malaria spreads through the bite of night-feeding mosquitoes. A net treated with insecticide does two jobs at once: it forms a physical barrier around a sleeping person and kills or repels the mosquitoes that land on it, which protects the whole community as mosquito numbers fall.

The story

Of all the tools aimed at malaria this century, the humble net has done the most. A 2015 study in Nature reconstructed two decades of malaria control across Africa and found that interventions had prevented hundreds of millions of cases, with insecticide-treated nets by far the largest contributor. It is cheap, low-tech, and one of the best-value lifesavers ever measured.

From the record

interventions have averted 663 (542-753 credible interval) million clinical cases since 2000

Bhatt et al. Nature, 2015 The effect of malaria control on Plasmodium falciparum in Africa, 2015

From the record

Insecticide-treated nets, the most widespread intervention, were by far the largest contributor (68% of cases averted).

Bhatt et al. Nature, 2015 The effect of malaria control on Plasmodium falciparum in Africa, 2015

Asked often

How effective are insecticide-treated bed nets?

A 2015 Nature study found that malaria interventions averted an estimated 663 million clinical cases in Africa since 2000, and that insecticide-treated nets were the single largest contributor, responsible for 68 percent of the cases averted.

Why do bed nets work so well against malaria?

They combine a physical barrier around a sleeping person with an insecticide that kills mosquitoes on contact, so they protect the whole community by reducing mosquito numbers, not just the individual under the net.

The next one is being invented now.

We send you the day's real progress every morning: the breakthroughs, the quiet wins, the proof it's still happening. Free, forever.