---
title: Insecticide-treated bed nets
summary: Nets treated with insecticide, hung over beds, that protect sleepers from the mosquitoes that carry malaria.
depth: 2
evidence: strong
mechanism: The net blocks mosquitoes while people sleep, and the insecticide kills mosquitoes that land on it, which also lowers malaria risk for people nearby.
causes: [global-health]
timeToEffect: immediate
durability: years
feedback: some
agency: top-down
cost:
  outcome: death averted (GiveWell’s modeled range for the places where it funds net campaigns)
  low: 3000
  high: 8000
  asOf: December 2023 cost-effectiveness analysis
  source:
    title: Mass Distribution of Insecticide-Treated Nets (ITNs)
    publisher: GiveWell
    year: 2023
    url: https://www.givewell.org/international/technical/programs/insecticide-treated-nets
  note: This is a model for net campaigns in the locations GiveWell funds, not a measured price for a life. The range varies by location and depends on malaria mortality, net use, how long nets last and what other funders would have paid for.
conditions: [story-bias]
sources:
  - title: Mass Distribution of Insecticide-Treated Nets (ITNs)
    publisher: GiveWell
    year: 2023
    url: https://www.givewell.org/international/technical/programs/insecticide-treated-nets
  - title: Insecticide-treated nets for preventing malaria (Cochrane systematic review)
    publisher: Joseph Pryce, Marty Richardson and Christian Lengeler, Cochrane Database of Systematic Reviews
    year: 2018
    url: https://pmc.ncbi.nlm.nih.gov/articles/PMC6418392/
---

## What the evidence says

Bed nets are among the most studied interventions in global health. A 2018 Cochrane review pooled five randomized trials with more than 200,000 participants. It found that, compared with no nets, insecticide-treated nets cut child deaths from all causes by about 17 percent, which works out to roughly 5.6 lives saved each year for every 1,000 children protected. The reviewers rated that evidence high-certainty.

## Where it sits on the depth scale

Nets are **prevention** (depth 2): they stop malaria for the people under them, and they keep working only while nets are replaced. They don’t change the conditions that let malaria persist, such as weak health systems or mosquito habitats. That is not a criticism. Prevention at this scale saves lives now, while structural work goes on.

## Open questions

- Insecticide resistance in mosquitoes is spreading, and newer nets use different chemicals. How long today’s effect sizes hold is an active research question.
- How nets are used day to day varies by place and season, which is why distribution programs track usage as well as delivery.