Insecticide resistance

During the last ten years, unprecedented progress has been achieved in malaria prevention and control. This has been mostly the result of a significant scaling up of vector control interventions around the world, particularly in sub-Saharan Africa. However, emerging resistance among Plasmodium parasites to antimalarial drugs and Anopheles mosquitos to insecticides are beginning to threaten these fragile gains.

According to the World Malaria Report 2012, insecticide resistance among Anopheles mosquitos has been detected in 64 countries around the world, affecting all major malaria vector species and all four existing classes of insecticides. Most affected countries have not yet carried out adequate routine monitoring (i.e. testing the efficacy of insecticides against local mosquito vectors), which means that our understanding of the scale of insecticide resistance is incomplete.

Endemic countries are urged to develop and implement comprehensive insecticide resistance management strategies and ensure timely entomological and resistance monitoring. Issued in May 2012, the Global plan for insecticide resistance management in malaria vectors (GPIRM) contains a global plan of action for all stakeholders engaged in the fight against malaria. It also contains comprehensive technical recommendations to manage insecticide resistance in different situations – including on the use of insecticide rotations for IRS.

If left unchecked, insecticide resistance could lead to a substantial increase in malaria incidence and mortality. The global malaria community needs to take urgent action to prevent insecticide resistance from emerging at new sites, and to maintain the effectiveness of existing vector control interventions. WHO is working with governments of endemic countries, donor organizations, UN agencies, and research and industry partners to implement the five-pillar strategy contained in the GPIRM, and has called for the development of new and innovative vector control tools and strategies.

The GPIRM has called for actions in the following five areas:

  • plan and implement insecticide resistance management strategies in malaria-endemic countries;
  • ensure proper, timely entomological and resistance monitoring and effective data management;
  • develop new, innovative vector control tools;
  • fill gaps in knowledge on mechanisms of insecticide resistance, the impact of current insecticide resistance management approaches
  • ensure that enabling mechanisms (advocacy, human and financial resources) are in place.

WHO susceptibility tests

WHO has a long tradition of providing support to countries in monitoring and managing insecticide resistance and this remains one of the core functions of the Global Malaria Programme (GMP). For standardization purposes, all supplies for WHO susceptibility tests should be ordered from the Universiti Sains Malaysia (USM), Penang, Malaysia, a WHO Collaborating Centre. Questions can be addressed to Dr Zairi Jaal:

Last update: 6 May 2013

Key documents