Once a localised threat, dengue fever has rapidly escalated into a global health emergency, putting nearly half the world's population at risk across more than 100 countries. As our world becomes increasingly interconnected through travel and trade, and in the face of climate change, the danger posed by this debilitating mosquito-borne disease looms larger than ever before.
Dengue is now the most widespread arboviral disease, with an estimated 390 million infections annually. Children under 10 years old are disproportionately impacted, being more susceptible to the disease than adults. For the 50-100 million people who develop symptoms (around 25 percent of those infected), they can experience severe headaches, pain behind the eyes, nausea, vomiting and joint pain so severe it has led to dengue also being coined 'break bone fever'. While Asia shoulders nearly 70 percent of the global dengue burden, the disease is also spreading at an alarming rate in Latin America and Africa due to rapid urbanisation, climate change and movement of people.
Areas of concern
South America, especially Brazil, has been severely affected, reporting a staggering 1.4 million dengue cases in 2022 alone -- the highest in the Americas region. The tropical climate, unplanned urban growth and inadequate vector control measures have created fertile breeding grounds for the Aedes mosquitoes that transmit the virus, leaving marginalised communities at an increased risk of infection.
The situation is equally concerning in Africa. Dengue is now endemic in Burkina Faso, which experienced over 150,000 suspected cases and just over 700 deaths in 2023 -- the largest dengue epidemic in Africa to date. Inadequate access to effective diagnostic tests for dengue makes the situation even more challenging. Cases are typically diagnosed according to the symptoms people exhibit. The problem is that many other illnesses have similar symptoms, which can result in dengue cases left undiagnosed and untreated. While some rapid diagnostic tests are in circulation, availability remains low and costs are high.
Uganda is also witnessing a worrying surge in dengue cases, with nearly 10 percent of the population carrying dengue antibodies. Densely populated urban areas, coupled with poor water and sanitation conditions, have become breeding grounds for the disease, disproportionately affecting children and outdoor workers.
Europe is not immune to this growing threat. The mosquito that carries dengue -- Aedes albopictus -- is now established in 13 European countries. Aided by increasingly favourable habitat conditions due to a warming climate, global mobility has enabled and quickened the importation of dengue into regions previously considered low risk, including the UK. There is an urgent need for globally coordinated efforts to stem the tide of this escalating crisis.
Bolstering defences through evidence and innovation
The World Health Organization's pre-qualification of a second dengue vaccine last month -- the TAK-003 developed by Takeda -- is a welcome step towards countering the spread of dengue. Dedicated vaccines can help to accelerate dengue prevention and control efforts and will be most effective when used in combination with existing tools such as diagnostic tests and insecticides, and strategies including point-of-care diagnosis (testing individuals outside of a laboratory, at locations where they first seek care).
Importantly, innovations to prevent arboviruses such as dengue must go hand-in-hand with sustained community engagement to increase awareness and encourage behaviours to seek treatment and control mosquito breeding sites. In Cambodia -- a country facing a high dengue burden -- Malaria Consortium previously led an innovative community-based dengue control initiative from 2018 to 2020. Empowered by this pioneering project to be agents of change, students were actively involved in mosquito monitoring, breeding guppy fish to control mosquito larvae and promoting behaviour change within their communities.
In Uganda, Malaria Consortium is implementing the Strengthening Uganda's Preparedness Against Arboviral Threats (SUPAAT) project in partnership with the Ministry of Health and Uganda Virus Research Institute. This comprehensive initiative will enhance arbovirus surveillance, diagnosis, response strategies and community engagement in high-risk districts including Wakiso and Bundibugyo. Healthcare workers are receiving specialised training, including in case management skills. Vector surveillance and control systems are being established, and a national arbovirus policy is being developed to safeguard vulnerable populations.
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Commitments to strengthen vector surveillance and reporting to build an accurate picture of the problem -- and sharing this knowledge and successful solutions -- are critical to improve national governments' preparedness to tackle this growing threat.
Since 2020, the six-year Resilience Against Future Threats through Vector Control (RAFT) Research Programme Consortium, funded by UK aid, has been at the forefront of addressing critical challenges in controlling Aedes-borne arboviruses like dengue. By generating vital evidence for governments and health leaders and providing opportunities for cross-learning between Southeast Asia and Africa, RAFT is helping ensure that national mosquito control strategies are strengthened to be effective and appropriate against rapidly evolving disease threats.
A united global effort
As the spread of dengue intensifies worldwide, it is clear that a united global effort is needed -- one that harnesses evidence-based strategies, innovative community engagement approaches and robust multi-sectoral partnerships. Only through concerted and collaborative action can we hope to turn the tide against dengue and safeguard the health and well-being of communities everywhere.
