The Global Malaria Programme (GMP) of the World Health Organization (WHO) put in place a framework for global malaria control and elimination efforts known as the Global Technical Strategy (GTS).

The GTS was developed in 2016 with ambitious targets on malaria control and elimination that were, at the time, deemed attainable. Progress towards many of these targets has, however, stalled over recent years, and the GTS, but not the targets, was revised in 2021 with a view of identifying solutions to get back on track towards reaching the set targets.

The GTS outlines the need for increased funding to allow accelerated implementation of available interventions in the form of comprehensive intervention packages tailored to local settings, rather than implementation of a ‘one size fits all’ approach across all malaria-endemic areas. It also emphasises the need for development, evaluation, and deployment of new interventions to mitigate the threat posed by insecticide and drug resistance. The need for new interventions to close gaps in the existing toolbox, such as vector control products designed to control outdoor biting and a malaria vaccine, is also highlighted.

The Vector Control and Insecticide Resistance Unit

Within the GMP, the Vector Control and Insecticide Resistance (VCR) unit oversees the development of vector control guidance to support the design and implementation of national malaria control strategies by WHO Member States. VCR also provides technical support to implement its guidance in close collaboration with WHO regional and country offices.

Guidance comes in two broad categories, namely a WHO guideline that contains WHO recommendations for/against specific interventions, and so-called ‘companion documents’ that provide practical guidance on the implementation of specific interventions.

In February 2021, GMP released the first ever consolidated malaria guidelines. These guidelines include recommendations on specific malaria vector control interventions. The guideline content is informed by systematic reviews of the currently available evidence on specific interventions such as insecticide-treated nets, indoor residual spraying or larviciding, and will evolve as new data on the efficacy of existing interventions are generated and as evaluations of new interventions are completed.

WHO Guidelines

WHO guidelines are largely ‘global’ rather than context-specific, which means that national malaria control programmes will need to adapt the content to meet their needs. There is no ‘one size fits all’ approach to malaria control/elimination. Instead, intervention packages need to be tailored to a specific context and to be commensurate with the available resources, through a prioritisation process that is country-led.

WHO supports the delivery of interventions by national programmes and their implementing partners by means of practical guidance. For malaria vector control, guidance is provided in the form of various manuals, such as the Operational Manual for Indoor Residual Spraying for Malaria Transmission Control and Elimination.

Not all WHO-recommended interventions have an associated companion manual. For some, such as for insecticide-treated nets (ITNs), detailed guidance is provided by partners, in this case by the Alliance for Malaria Prevention in collaboration with WHO.

In addition to practical guidance, GMP provides technical support on planning, implementation, and evaluation of malaria control programmes.

Insecticide Resistance

As mentioned above, a major threat to malaria control efforts is the development and spread of insecticide resistance. In the late 1960s, insecticide resistance was one of the reasons for the abandonment of the Global Malaria Eradication Programme.

Nowadays, this threat is as evident as back then. Out of 82 malaria-endemic countries that provided data for 2010–2019 to WHO, 28 detected resistance to all four of the most commonly used insecticide classes in at least one malaria vector and one collection site, and 73 detected resistance to at least one insecticide class.

In recognition of the threat of insecticide resistance and to support the management of this threat, GMP developed the Global Plan for Insecticide Resistance Management in malaria vectors (GPIRM) in 2012. GPIRM calls on governments of malaria-endemic countries, donor organisations, UN agencies, as well as research and industry partners, to implement a five-pillar strategy to tackle the growing threat of insecticide resistance and to facilitate the development of innovative vector control tools and strategies.

The concepts of GPIRM have, more recently, been incorporated into the Global Vector Control Response (GVCR) 2017-2030, a new strategy developed to strengthen vector control worldwide. The GVCR was developed when the 2015-2016 Zika virus epidemic made it apparent that the world had dropped the ball on mosquito control. Building on the concept of integrated vector management, the GVRC promotes a four-pillar strategy to develop and implement effective, locally adapted and sustainable vector control.

Outlook

Opportunities to enhance vector control capacity, improve surveillance and to better coordinate and integrate action across sectors and diseases abound. A prime example of this is the response to the invasion of Anopheles stephensi in the Horn of Africa, an efficient malaria vector that shares its ecology with Aedes aegypti, the predominant vector of dengue and other arboviruses in this part of the world. Which, therefore, lends itself to integrated surveillance and control activities.

Author: Jan Kolaczinski

Links

WHO Global Malaria Programme

Global plan for insecticide resistance management in malaria vectors (GPIRM)

Global vector control response (GVCR) 2017–2030