Insecticide resistance

Last update: 7 November 2017

The past 15 years have seen unprecedented progress in malaria prevention and control. This has mainly been the result of a significant scaling up of vector-control interventions, particularly in sub-Saharan Africa. However, these fragile gains are threatened by emerging resistance to insecticides among Anopheles mosquitoes and to antimalarial medicines among Plasmodium parasites.

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 an increase in insecticide resistance, and to maintain the effectiveness of existing vector-control interventions.

Insecticide resistance already widespread

Resistance is known to affect all major malaria vector species and all four recommended classes of insecticides. Since 2010, a total of 61 countries have reported resistance to at least one class of insecticide, with a 50 of those countries reporting resistance to 2 or more classes. However, our understanding of the extent of the problem is incomplete, because:

  • many countries do not carry out adequate routine monitoring for insecticide resistance in local vectors; and
  • monitoring data are often not reported in a timely manner.

Global action plan developed

Issued in May 2012, the WHO Global plan for insecticide resistance management in malaria vectors (GPIRM) is a global plan of action for all stakeholders engaged in the fight against malaria. The document provides comprehensive technical recommendations to manage insecticide resistance in different situations.

The GPIRM calls for the following key actions to be undertaken:

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

More action urgently needed

The uptake of GPIRM at national levels has been somewhat limited, in part due to a critical lack of financial and human resources and of infrastructure. A recent situation analysis evaluated progress made and challenges experienced in implementation. The analysis outlined key actions required to address insecticide resistance in line with GPIRM.

WHO continues to work with governments of endemic countries, donor organizations, United Nations agencies, and research and industry partners to implement the 5-pillar strategy contained in the GPIRM including supporting the development of new and innovative vector-control tools and strategies.

Endemic countries are urged to develop and implement comprehensive insecticide-resistance management strategies, and ensure timely entomological and resistance monitoring.

WHO global insecticide resistance database

The database consolidates information collected on the status of insecticide susceptibility of Anopheles mosquitoes in malaria-endemic countries. It is the largest and most up-to-date collection of insecticide bioassay data reviewed and standardized for analysis. These data are needed to inform national and global malaria vector-control policy and implementation.

Key documents

WHO susceptibility tests

All supplies for WHO insecticide 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: