What are the current WHO and national policies on using DDT for malaria control and what ecological safeguards accompany those programs?
Executive summary
WHO currently endorses the targeted use of DDT for indoor residual spraying (IRS) as one tool among several for malaria control, while emphasizing reduced reliance on DDT and promoting alternatives where feasible [1] [2]. National policies vary: some countries retain DDT for IRS under exemptions in the Stockholm Convention and WHO guidance, while others have phased it out; programmes are expected to operate under entomological evidence, resistance management and environmental safeguards [3] [4].
1. What WHO actually recommends on DDT now
WHO’s consolidated malaria guidance and recent guideline revisions keep IRS as an approved malaria intervention and list DDT among WHO‑approved IRS insecticides, but the Organization has shifted tone since earlier eras—endorsing small, well‑managed indoor spraying campaigns only where indicated and stressing reduced use as new insecticides and tools become available [1] [5] [2]. WHO guidance updates in 2025 incorporated evidence on new IRS insecticides (chlorfenapyr and isocycloseram) while explicitly emphasizing reduced use of DDT and continued reliance on a broader toolbox [2] [6].
2. International legal framework and national discretion
DDT is listed as a persistent organic pollutant under the Stockholm Convention but the treaty contains an explicit exemption allowing public‑health use for disease vector control consistent with WHO guidance; therefore national governments can register and use DDT for IRS if they meet the Convention’s acceptable‑purpose provisions [3] [7]. Global production and use have fallen over the 2001–2014 period, yet several countries continued to produce or use DDT for vector control in recent years, underscoring that national policy choices remain heterogeneous and subject to international reporting requirements [3] [4].
3. How countries are actually using (or not using) DDT
A shrinking group of countries have continued DDT use for IRS into the 2020s—India, South Africa and Zimbabwe were cited as still using it in 2023 while others keep it as an emergency option—with many nations moving away as alternatives and policy pressures mount [4]. Historical context matters: WHO’s early eradication campaigns relied heavily on outdoor and indoor DDT spraying in the mid‑20th century, but concerns about environmental contamination and health prompted a shift away from large‑scale promotion in the 1980s and renewed, more constrained endorsement from the 2000s onward [8] [5].
4. Ecological and programmatic safeguards WHO and others attach to IRS with DDT
WHO and related technical literature require that DDT be used within integrated vector management (IVM) frameworks grounded in entomological surveillance, insecticide‑resistance monitoring, and evidence of epidemiological need, and that IRS be limited to indoor residual applications (not agricultural or wide environmental spraying) to minimize ecological exposure [8] [9] [5]. WHO and the Stockholm Convention approach emphasize well‑managed programmes—trained applicators, safe storage and disposal, and monitoring of human exposures and environmental residues—because multiple reviews cited by WHO concluded that carefully run IRS limits direct harm to humans and wildlife relative to historic widespread uses [5] [9].
5. Criticisms, trade‑offs and why the debate continues
Public‑health advocates point to DDT’s efficacy, low acute mammalian toxicity, long residual activity and cost advantages as reasons to retain it for IRS in high‑burden, resource‑limited settings, while environmental and health experts warn of chronic exposures, reproduction and other possible long‑term effects and urge use only when no safe, effective and affordable alternatives exist [10] [11]. Independent reviews and journal reporting highlight trade‑offs—potential economic health costs from exposure versus the massive burden of untreated malaria—and stress that resistance in mosquito populations and export‑market concerns (e.g., agricultural contamination) complicate national choices [10] [12] [3].
6. Bottom line: conditional, monitored, and shrinking role for DDT
The policy arc is clear in the sources: DDT remains an authorized, last‑resort public‑health insecticide for IRS under WHO guidance and Stockholm Convention exemptions, but WHO’s recent guidelines press for reduced use, routine entomological justification, strict programme management and active pursuit of alternatives; national policies reflect local epidemiology, capacity, resistance patterns and trade/environmental concerns [2] [1] [3] [4]. Where sources do not provide specific national statutes or real‑time programme audits, reporting limits prevent verification of on‑the‑ground compliance with safeguards.