The geographical reach of arboviral diseases is rapidly growing. Climate pressures, urbanisation, overstretched health systems, lack of reliable point of care diagnostics and gaps in surveillance and reporting are seeing diseases like dengue emerging in new countries.
In Africa and Latin America, dengue is becoming an increasingly urgent public health concern. And as health budgets tighten and global priorities continue to shift, national health programmes are facing tough decisions on what to prioritise. The result is often a fragmented response that has profound consequences for who is diagnosed, who receives timely care and who is at risk of progressing to severe disease.
Every year, dengue infects an estimated 100-400 million people. Its burden has grown dramatically in the last two decades, from just over 500,000 reported cases in 2000 to 14.6 million cases and 12,000 deaths reported in 2024. However, since most of these cases are asymptomatic or mild, case numbers are often under-reported, hiding the true burden.
Dengue is one of the fastest-growing infectious diseases in the world. Without a more coordinated approach, the world risks widening the gaps that already exist: missed or delayed diagnosis, disruptions to care including extreme weather events and conflict, and the continued absence of a widely available, effective treatment. The result? Increased pressure on already stretched health systems, particularly during outbreaks, where these gaps can often be the difference between life and death.
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The cost of invisibility
For dengue and other arboviral diseases, early recognition is an imperative, particularly in settings with limited access to healthcare. Arboviral diseases like dengue often present with symptoms similar to other diseases such as malaria, which means cases are frequently misdiagnosed and under-reported.
There is a narrow window between initial infection and the development to severe dengue. Patients who are identified early can be monitored and referred to health facilities in good time. Those who are missed may deteriorate rapidly, arriving at hospitals in a critical condition — or they may never get there at all. Patients also report symptoms that linger after the infection, such as weakness, headache, fever and fatigue, which in turn have social and economic ramifications.
Prudence Hamade, a senior technical advisor at Malaria Consortium, experienced the importance of an early diagnosis firsthand when she contracted dengue while working during an outbreak in Cambodia in 2001. One morning, she woke up feeling off colour and very tired, she recalls. She put it down to the intense workload, as she was managing a large non-profit project supporting the local authorities to run a hospital and 17 health centres.
“There was a big dengue outbreak in progress, and the hospital was full of cases. It was so busy that, sometimes, we had three children to a bed,” she says. She ignored her symptoms and continued to work. But eventually, she was tested, with the results confirming dengue serotype 2, one of the four dengue serotypes that exist.
“By that point, I was unable to get out of my bed,” she says. She developed a bright red rash from head to toe and was confined to bed for a week. It took about three months before she felt truly well again.
She not only was a spectator to the serious fallout of an outbreak, but also found out for herself just how painful the infection, known as ‘break bone fever’, can be. “As I saw firsthand, both through my personal experience and what I witnessed during outbreaks in endemic regions, dengue can have a serious effect not only on the health and wellbeing of individuals, but also of entire nations,” she says.
Catching diagnosis earlier to save lives later
When cases go undiagnosed, they become invisible to surveillance systems. This makes it trickier to determine where the disease is circulating, and where to deliver resources for the greatest impact.
In Uganda, the problem of diagnosis is being addressed as one of the critical gaps in the country’s arboviral response. Malaria Consortium’s Strengthening Uganda’s Preparedness Against Arboviral Threats (SUPAAT) project in partnership with the Ministry of Health and Uganda Virus Research Institute is bolstering the country’s defence against mosquito-borne viruses through enhanced surveillance, diagnosis, response strategies and community engagement.
The planned introduction of rapid diagnostic testing (RDTs) to quickly and accurately screen for mosquito-borne fevers including dengue, means cases can be caught early. This would lead to speedier triage and case management. RDTs would enhance the current 7-1-7 framework, which states outbreaks should be detected within seven days, investigated within a day of detection and the response initiated within seven days.
Better rapid testing also generates more accurate surveillance data, which is essential for spotting and controlling outbreaks early. Together, this means patients can be identified sooner, monitored and supported before their condition becomes severe.
Our previous work to tackle dengue in Cambodia and Myanmar underscored the importance of community trust in health programmes, and the vital role that community health workers and communities themselves play in this ecosystem. Operating at the interface between communities and health systems, health workers are often the first point of contact for people who have fallen ill.
Equipping and supporting these workers to recognise the warning signs of dengue, conduct basic assessments and facilitate timely referral can be transformative in settings where qualified clinicians are scarce.
In Uganda, the SUPAAT project is supporting community members to understand how arboviral diseases spread and what steps they can take to protect themselves, through public awareness campaigns, surveys and local engagement.
But detection and diagnosis paint only part of the response picture. The lack of a treatment for dengue points to the urgency of accelerating the development of effective treatments, as well as the risks of deprioritising research and development (R&D) for neglected diseases in the current funding landscape, despite its critical role in preventing severe illness and death.
Closing the treatment gap: Why investment in R&D is urgent
Despite the stakes, there is currently no existing treatment for dengue, although pain can be managed through medication. Two vaccines have been developed, but their use is limited. Devoting resources to the development of effective treatments is now a matter of urgency.
Organisations such as Drugs for Neglected Diseases initiative (DNDi) are working to repurpose existing drugs to develop antivirals that work against dengue. Six vaccine candidates are currently being tested in clinical trials, and require continued investment to ensure that new, improved options reach the market.
Better diagnostics, such as those being introduced in Uganda and elsewhere, is a crucial part of progress, but their value is constrained by what comes next. Early diagnosis enables faster response and closer monitoring, but it does not change what can be offered to a patient who tests positive. Investment in R&D is therefore critical to improving outcomes for patients.
The history of neglected tropical diseases offers a lesson: diseases that predominantly affect lower-income countries sometimes struggle to attract sustained R&D investment, and the resulting gap in tools translates into potential lives lost and overwhelmed health systems.
Previous disease outbreaks, such as COVID-19, and recurring outbreaks such as Ebola, have shown that funding tends to follow a crisis rather than prevent it, arriving once the burden is already severe. Dengue cannot afford to wait for that moment.
Knowledge-sharing across the world
Dengue’s geographical footprint is vast, spanning Africa and southeast Asia — endemic regions where Malaria Consortium implements health interventions — as well as Latin America.
Dengue isn’t limited by borders, and so tackling it requires coordinated, cross-country responses. Lessons learnt about community-level diagnosis and care-seeking in Cambodia or Uganda may be directly relevant to communities in Brazil or Colombia. The collective knowledge of the dengue research community is one of its most valuable assets.
Strengthening the connections between implementers and researchers — between those working at the frontline and those developing the tools of the future — is essential. In a constrained funding landscape, these collaborations can be challenging to sustain, despite their importance for an effective response. Too often these communities also work in parallel, separated by institutional boundaries, funding silos or simple distance. Bridging that divide is one of the most important investments the global health community can make.
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Initiatives like the Resilience against Future Threats (RAFT) research consortium, led by the London School of Hygiene and Tropical Medicine, has shown the value of cross-regional collaboration. Under the six-year initiative, Malaria Consortium supported four African countries- Burkina Faso, Cameroon, Côte d’Ivoire and Tanzania, to undertake self-assessments to examine how prepared each respective country is for an outbreak of a vector-borne arboviral disease — including dengue, chikungunya and yellow fever — and to then develop national strategic plans to tackle such a crisis.
The research programme empowered national governments and health leaders to ensure that national mosquito strategies are effective and appropriate in the face of new and changing mosquito-borne disease threats, particularly in Africa.
The path forward
The world is at a turning point in the fight against dengue. We know what is needed: better diagnostics, improved and affordable vaccines, effective insecticides for mosquito control, stronger surveillance systems and a path towards new treatments.
At a time when resources have never been more strained, moving the needle will require targeted and sustained investment and tight collaboration. And coordination must extend beyond the health sector. Dengue sits at the intersection of climate, urban planning, water management and education. Responses that fail to account for this will remain insufficient. Equally, the communities most affected by dengue are not simply recipients of top-down interventions; their knowledge and experience must actively shape the solutions. Together, we can turn the tides on this rapidly expanding threat.
