A new Cochrane evidence and gap map (EGM) has mapped the global research landscape on dengue prevention, finding plenty of research but not enough of it synthesized in ways policymakers can use.
Dengue is one of the most rapidly spreading infectious diseases in the world. Spread through the bites of the infected Aedes aegypti mosquito, the global threat posed by dengue has been rising for years, as climate change, urbanization and international travel aid the spread of the mosquitoes that transmit it. Brazil reports some of the highest dengue case numbers globally, with the disease disproportionately impacting communities affected by adverse social, economic, and environmental conditions.
Published in the Cochrane Database of Systematic Reviews, this is the first comprehensive evidence and gap map consolidating primary studies and systematic reviews on dengue prevention strategies. It finds that while hundreds of studies exist, only a small fraction have been synthesized into reliable, high-quality systematic reviews that policymakers and funders can act on.
"There's a lot of evidence out there, covering community education, vector control, vaccines, and environmental interventions," says Dr Bruno Guedes, co-first author from Federal University of Piauí, Brazil. "However, our gap map revealed some important gaps in the evidence regarding systematic reviews, especially for adult vector and aquatic-stage interventions, as well as for implementation and behavioural outcomes.”
Where the gaps are
Community education is one of the best-documented areas, drawing on 47 randomized trials and 140 non-randomized studies. It includes engaging with communities to stop mosquitoes from breeding and prevent the spread of the virus, focusing on practical steps like clearing standing water, involving local schools, and working with community leaders to build long-term safety habits. Even so, there is a lack of evidence whether these types of interventions make an impact to the spread of the disease itself. This is a common theme among interventions that target mosquitoes.
Beyond community education, the map identified other important gaps. For adult mosquito control, existing reviews are generally outdated, with the exception of one recent review focused on the Wolbachia approaches. Interventions targeting the aquatic, or larval, stage of the mosquito show synthesis gaps spanning all outcome areas. For vaccines, evidence on implementation is limited, and behavioural outcome evidence is essentially absent. And for environmental interventions, primary studies exist, but behavioural and implementation outcomes still lack quality systematic reviews.
“We were most surprised by the lack of synthesized evidence on dengue vaccines in the adult population,” explains Leslie Choi, co-first author and Evidence Synthesis Development Editor at Cochrane. “Dengue vaccines have been studied in many clinical trials, especially regarding safety and disease prevention. However, we still need more evidence on how vaccination programs work in real-life public health settings. This is an area in which Cochrane is looking to commission reviews.”
Which gaps are the highest priority
The EGM was designed to equip policymakers with gap maps tailored to their local health priorities, helping them identify critical knowledge gaps to inform future primary research and systematic reviews at the local level.
Policymakers and civil society representatives were directly involved in the process, and stakeholders prioritized research on adverse effects across four areas. In no particular order, these are:
- Environmental interventions
- Community education
- Interventions targeting aquatic stages of the vector
- Interventions targeting adult vectors
What this means
The author team call for updated, comprehensive systematic reviews on vector control interventions, stronger synthesis of implementation and behavioural evidence across non-vaccine strategies, and more systematic evaluation of adverse effects beyond vaccines.
"The main issue isn't that we lack dengue prevention research; it's that the research hasn't been synthesized in ways that are useful for decision-making," says Dr Guedes. “Busy policymakers and public health officials need clear answers to basic dengue questions. Currently, those questions are left unanswered.”
The authors also caution that an overreliance on entomological outcomes, such as mosquito counts, is insufficient on its own. Greater emphasis on epidemiological and real-world implementation outcomes, they argue, is essential for designing dengue control strategies that are effective, scalable, and appropriate to local contexts.
About the evidence and gap map
The map was produced using Cochrane Crowd, Cochrane's citizen-science platform, together with EPPI Reviewer and EPPI Mapper software to code and visualize the evidence. Stakeholder engagement was conducted in partnership with Instituto Veredas, a Brazilian NGO working at the intersection of public management, academia, and civil society. The interactive online map allows funders, policymakers, and researchers to explore the evidence base by intervention type and outcome, and to identify where future research investment is most needed.
Facts Only
* A new Cochrane evidence and gap map has been published mapping global research on dengue prevention.
* Dengue spreads through bites from the *Aedes aegypti* mosquito.
* Brazil reports some of the highest global dengue case numbers.
* The map consolidates primary studies and systematic reviews on dengue prevention strategies.
* Only a small fraction of existing research has been synthesized into reliable, high-quality systematic reviews for policymakers.
* Gaps exist in systematic reviews concerning adult vector and aquatic-stage interventions.
* Evidence on vaccine implementation and behavioral outcomes is limited.
* Stakeholders prioritized research across four areas: environmental interventions, community education, aquatic stage interventions, and adult vector interventions.
* The authors call for updated systematic reviews on vector control interventions and stronger synthesis of implementation/behavioral evidence.
Executive Summary
A new Cochrane evidence and gap map has been created to synthesize global research on dengue prevention, identifying a significant gap between existing research and the needs of policymakers. The map consolidates primary studies and systematic reviews related to dengue prevention strategies. While hundreds of studies exist, only a small fraction have been synthesized into high-quality reviews actionable by decision-makers.
The evidence map highlights specific deficiencies across various intervention areas. Community education is well-documented through numerous trials, yet there is a lack of evidence on its impact on disease spread. Gaps are also evident in systematic reviews concerning adult vector control and aquatic-stage interventions. Evidence regarding dengue vaccines faces limitations concerning real-life implementation outcomes and behavioral results.
The map prioritized research needs based on stakeholder input, focusing on environmental interventions, community education, interventions targeting aquatic stages, and interventions targeting adult vectors. This signals a need for updated, comprehensive systematic reviews, particularly concerning vector control strategies and the synthesis of implementation and behavioral evidence across non-vaccine methods.
Full Take
The process of creating a gap map shifts the focus from the mere existence of research to its usability for action. The core tension revealed is not a deficit of data, but a deficiency in synthesis and contextualization. Policymakers are seeking clear answers, but the existing evidence is fragmented across specific intervention types (e.g., community education versus adult vector control). This creates an opportunity for structured knowledge building rather than just accumulating studies.
The prioritization by stakeholders—focusing on environmental factors and community engagement alongside vector control—suggests a systemic acknowledgment that purely entomological metrics are insufficient for effective public health strategy. The request for emphasis on epidemiological and real-world implementation outcomes over raw entomological counts points toward a potential pattern where scientific rigor must intentionally incorporate socio-behavioral realities to achieve scalable solutions.
The implication is that the current research ecosystem rewards descriptive data but under-rewards integrated, actionable knowledge. For future progress, the challenge lies in developing methodologies that systematically bridge the gap between laboratory findings and real-world behavioral implementation, ensuring that synthesized evidence directly informs context-specific decision-making rather than just cataloging what has been studied.
Bridge Questions: What mechanisms are necessary to reliably translate complex observational or behavioral data into high-quality evidence suitable for systematic review? How can funding structures be reformed to incentivize the synthesis of implementation outcomes alongside intervention efficacy? What organizational changes are required within health bodies to prioritize and operationalize these newly identified knowledge gaps in ongoing research agendas?
Sentinel — Human
This analysis appears to be grounded in genuine research reporting, characterized by the structured presentation of findings and direct engagement with expert commentary, suggesting a human editorial origin.