A surreal illustration depicting malaria prevention in Ethiopia, combining imagery of mosquito nets, villages, and symbols of health and economic development.

Malaria Prevention: Is Combining Bed Nets and Spraying Worth the Cost?

Rhea Morgan in Health & Wellness December 2025 • 4 min read.

"A new study from Ethiopia weighs the cost-effectiveness of different malaria prevention strategies, revealing surprising insights for public health officials."

Malaria remains a significant public health challenge in many parts of the world, demanding effective and affordable prevention strategies. Two widely used interventions are long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS), both proven to reduce malaria transmission. However, the question of whether combining these methods offers a cost-effective advantage over using them separately has been a subject of ongoing debate.

A recent study conducted in Ethiopia delved into this very question, comparing the cost-effectiveness of combined LLIN and IRS implementation against LLINs alone, IRS alone, and routine practices. The findings offer valuable insights for public health officials and policymakers grappling with resource allocation decisions in malaria prevention.

This article breaks down the study's methodology, results, and conclusions, providing a clear understanding of the economic implications of different malaria prevention strategies. We will explore the factors that influence cost-effectiveness and highlight the key takeaways for optimizing malaria control efforts.

The Cost-Effectiveness Conundrum: LLINs, IRS, or Both?

A surreal illustration depicting malaria prevention in Ethiopia, combining imagery of mosquito nets, villages, and symbols of health and economic development.

The Ethiopian study employed a rigorous approach to assess the cost-effectiveness of different malaria prevention strategies. Researchers conducted a cluster randomized controlled trial in the Adami Tullu district, following households over a period from 2014 to 2016. Alongside this trial, they performed a literature-based cost-effectiveness analysis, drawing on effectiveness data from a systematic review of published articles.

The study meticulously accounted for the costs of each intervention from the provider's perspective, including expenses related to insecticide, nets, personnel, transportation, and training. Health outcomes were measured using disability-adjusted life years (DALYs) averted, a metric that combines years of life lost due to premature death and years lived with disability.

Routine Practice: Relied on existing malaria control activities, with a baseline LLIN coverage of 11%.
LLINs Alone: Universal coverage with long-lasting insecticidal nets, ensuring every household received nets based on family size.
IRS Alone: Universal coverage with indoor residual spraying using Propoxur, conducted annually.
Combined Intervention (LLINs + IRS): Integrated both LLIN distribution and indoor residual spraying.

The researchers then used a Markov life-cycle model to combine cost and health outcome data, allowing them to project the long-term impact of each intervention. Both trial-based data and literature-based scenarios were analyzed to provide a comprehensive picture of cost-effectiveness.

Key Takeaways: Making Informed Decisions

The Ethiopian study provides critical insights for malaria prevention efforts. While the trial-based analysis suggested that routine practices were more cost-effective due to lower costs and similar health outcomes, the literature-based analysis painted a different picture. This analysis indicated that LLINs alone are likely cost-effective compared to a willingness-to-pay threshold of three times Ethiopia's GDP per DALY averted.

The cost-effectiveness of the combined intervention (LLINs + IRS) hinges on several factors, particularly the annual malaria probability in the area and the protective-effectiveness of the combined approach. The study revealed that the annual malaria incidence needs to be at least 13% and the protective-effectiveness of combined implementation should be at least 53% for the combined intervention to be considered cost-effective.

Ultimately, the decision of which malaria prevention strategy to implement requires careful consideration of local context, including malaria transmission rates, intervention costs, and the desired level of protection. By understanding these factors, public health officials can make informed decisions to optimize resource allocation and maximize the impact of malaria control programs.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1186/s12962-018-0164-1, Alternate LINK

Title: Cost-Effectiveness Of A Combined Intervention Of Long Lasting Insecticidal Nets And Indoor Residual Spraying Compared With Each Intervention Alone For Malaria Prevention In Ethiopia

Subject: Health Policy

Journal: Cost Effectiveness and Resource Allocation

Publisher: Springer Science and Business Media LLC

Authors: Alemayehu Hailu, Bernt Lindtjørn, Wakgari Deressa, Taye Gari, Eskindir Loha, Bjarne Robberstad

Published: 2018-11-22

Everything You Need To Know

What were the primary malaria prevention strategies investigated in this study?

The study compared the cost-effectiveness of four malaria prevention strategies: Routine Practice, LLINs Alone, IRS Alone, and Combined Intervention (LLINs + IRS). Routine Practice relied on existing malaria control activities, with a baseline LLIN coverage. LLINs Alone provided universal coverage with long-lasting insecticidal nets. IRS Alone involved universal coverage with indoor residual spraying using Propoxur. The Combined Intervention integrated both LLIN distribution and indoor residual spraying. The researchers assessed the costs from the provider's perspective, including expenses for insecticide, nets, personnel, transportation, and training. Health outcomes were measured using disability-adjusted life years (DALYs) averted to determine which strategy offered the best value for public health investments.

What roles do Long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) play in malaria prevention, and how were they used in the study?

Long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) are both proven methods to reduce malaria transmission. LLINs act as a physical barrier and deliver insecticide, while IRS involves spraying insecticide on indoor surfaces where mosquitoes rest. In this study, the use of Propoxur in IRS was examined. The study aimed to determine if combining these methods offered a cost-effective advantage over using them separately, as the debate on the optimal use of resources is ongoing.

How did the researchers conduct the study and analyze the data to assess the cost-effectiveness of the different malaria prevention strategies?

The study employed a cluster randomized controlled trial in the Adami Tullu district in Ethiopia, following households from 2014 to 2016. Alongside the trial, researchers conducted a literature-based cost-effectiveness analysis. The study used a Markov life-cycle model to combine cost and health outcome data, projecting the long-term impact of each intervention. Researchers meticulously accounted for the costs of each intervention, including those for insecticide, nets, personnel, transportation, and training. Health outcomes were measured using disability-adjusted life years (DALYs) averted.

What were the main conclusions of the study, and what do they mean for malaria control?

The study's key findings offer valuable insights for public health officials. The trial-based analysis suggested that Routine Practices were more cost-effective due to lower costs and similar health outcomes. However, the literature-based analysis indicated that LLINs Alone are likely cost-effective compared to a willingness-to-pay threshold of three times Ethiopia's GDP per DALY averted. These findings are important because they help in making informed decisions about resource allocation in malaria prevention programs.

How did the study assess the economic implications of the different malaria prevention strategies, and what is the significance of using disability-adjusted life years (DALYs)?

The study focused on the economic implications of different malaria prevention strategies, using disability-adjusted life years (DALYs) averted to measure health outcomes. DALYs combine years of life lost due to premature death and years lived with disability. The study calculated the costs from the provider's perspective and measured the effectiveness of different interventions. By considering the costs and health benefits, the researchers could determine which strategies provide the best value, helping public health officials optimize malaria control efforts.