MADRID, 13 (EUROPA PRESS)
In the latest update to its malaria guidelines, the World Health Organization (WHO) has recommended the use of spatial repellents to control the mosquito that transmits the disease, introducing a new type of intervention at a time when innovation is "urgently" needed.
These spatial repellents release active ingredients into the air to kill mosquitoes, keep them away from certain areas, and prevent them from locating and biting human hosts. They thus serve as a complement to other preventive measures, such as insecticide-treated mosquito nets and indoor residual spraying.
According to the WHO, these types of repellents offer an advantage over mosquito nets by providing an additional layer of protection against mosquito bites during the day, when residents of a home are active inside the house and not sleeping under the net.
The WHO's acting director of Malaria and Neglected Tropical Diseases, Daniel Ngamije, has highlighted this new recommendation in light of the "growing resistance" to insecticides and "behavioral changes" among mosquitoes, which threaten the effectiveness of traditional control tools.
"At a time when progress against malaria has stalled, spatial repellents are the first type of vector control intervention in decades, offering a new approach to protecting people at risk," emphasized Unitaid Executive Director Philippe Duneton.
Despite the significant progress represented by this conditional recommendation, based on five studies, the WHO has pointed out that significant gaps in the scientific evidence remain, particularly regarding the effectiveness of spatial repellents when used alone, their potential to protect people outdoors or in humanitarian emergencies, and their role in managing insecticide resistance.
In this regard, WHO's global research and funding partners are working to address these gaps and strengthen the scientific basis on space emanations.
TWO PRE-QUALIFIED SPACE REPELLENTS
The WHO has also prequalified the first two spatial repellent products, Mosquito Shield and Guardian, manufactured by SC Johnson & Son. These products emit the active ingredient transfluthrin, which repels, disorients, and kills malaria-carrying mosquitoes.
Their effectiveness has been shown to last up to one month and 12 months, respectively, meaning they can be implemented in a variety of settings where replacement strategies and distribution schedules may vary.
Furthermore, the potential of spatial repellents to reduce the transmission of dengue and other arboviruses is being evaluated. Results from an initial trial in Peru revealed a reduction in arbovirus infection in the study population; a second trial in Southeast Asia has just been completed, and analyses are ongoing.
Data from these trials, which range from malaria to arboviral diseases, will inform future deliberations by relevant WHO guideline development groups, potentially leading to new or updated recommendations for the expanded use of space-based emanators.
