A new international study has found that insecticide-treated mosquito nets (ITNs) continue to significantly reduce malaria cases and deaths. However, rising insecticide resistance among mosquitoes could weaken their effectiveness in the future.

The study, published in the peer-reviewed journal Infectious Diseases, found that ITNs remain one of the most effective and affordable tools for malaria prevention. However, researchers warned that growing resistance to insecticides and changes in mosquito behaviour could undermine the long-term impact of the intervention, particularly in areas where resistance is already widespread.

The analysis, which reviewed 25 studies conducted across Africa and Asia, showed that insecticide-treated nets reduced malaria cases by as much as 68 per cent and highlighted emerging challenges that could threaten future gains in malaria control.

Researchers noted that although ITNs continue to provide strong protection against malaria, their effectiveness varies considerably across regions and communities due to differences in mosquito species, levels of insecticide resistance, environmental conditions and consistency of net usage.

The study’s lead author, Dr Gbeminiyi Otolorin, a doctoral researcher at James Cook University, Australia, and a veterinary public health clinician and researcher at the Faculty of Veterinary Medicine, University of Jos, said the findings reinforce the importance of mosquito nets while underscoring the need for continued vigilance.

“While the study reinforces that ITNs remain one of the most powerful weapons against malaria, it is also a warning that we cannot afford to become complacent,” Otolorin said.

He explained that mosquitoes are increasingly developing resistance and adapting their behaviour, making it necessary for malaria control programmes to continuously assess and adjust their strategies.

“A tool that works well in one place may already be failing in another. We must continuously monitor, evaluate and tailor our control strategies as we strive towards global elimination of the disease,” he added.

According to Otolorin, the findings should serve as both reassurance and a warning for policymakers and public health authorities.

Malaria remains a major public health challenge globally, affecting millions of people each year, particularly in tropical and subtropical regions. Insecticide-treated mosquito nets have long been a cornerstone of malaria prevention because they provide both a physical barrier and a chemical defence against disease-carrying mosquitoes.

The study found that in Asia, ITN use was associated with a 68 per cent reduction in malaria cases and an 18 per cent reduction in malaria-related deaths. In Africa, where the burden of malaria remains highest, the nets reduced malaria incidence by between 29 and 40 per cent.

Researchers reviewed 19 studies focused on malaria incidence and six studies examining malaria-related mortality. Collectively, the findings showed that ITNs continue to play a critical role in protecting vulnerable populations and reducing disease transmission in malaria-endemic areas.

Despite these gains, the researchers identified several factors that influence the effectiveness of mosquito nets, including insecticide resistance among mosquito populations.

Experts explained that insecticide resistance occurs when mosquitoes gradually develop the ability to survive exposure to chemicals that previously killed them. As resistance increases, the protective benefits of insecticide-based interventions can diminish, making malaria control more difficult.

To address this challenge, the researchers recommended the wider deployment of next-generation mosquito nets, including pyrethroid-piperonyl butoxide (PBO) nets and other dual-active-ingredient ITNs designed to overcome resistance and improve protection.

They also advocated integrating mosquito nets into broader vector-control programmes that combine multiple interventions. Such measures include indoor residual spraying, insecticidal wall linings, environmental management and other community-based strategies aimed at reducing mosquito populations and limiting disease transmission.

Public health experts stressed that ongoing monitoring of insecticide resistance will be critical to sustaining progress against malaria. Regular surveillance, they said, would help health authorities identify areas where conventional interventions are losing effectiveness and introduce alternative measures before outbreaks occur.

The study concluded that while insecticide-treated mosquito nets continue to save lives and remain highly effective, malaria control programmes cannot depend indefinitely on a single intervention.

The researchers called for sustained investment in research, innovation and integrated disease-control strategies to preserve the gains achieved over the past decades.

They added that as countries pursue the long-term goal of malaria elimination, adapting interventions to local conditions and emerging challenges will be essential. According to the researchers, the future success of mosquito nets will depend not only on widespread use but also on the ability of health systems to stay ahead of evolving mosquito populations.