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The impacts of global warming and changes in climate are linked to 23% of all deaths around the globe1. The burden and incidence of climate-sensitive diseases like dengue have dramatically increased. Changing rainfall patterns, urbanisation leading to heat islands within cities, and an increased number of heat waves/hot days contribute to the increasing dengue burden. Research has shown that the dengue virus is affected by temperature changes resulting in increased flying range, increased duration of activity and shorter extrinsic incubation period1. Dengue case numbers and its spread have also been shown to have a high direct correlation to the number of hot days, heat waves and warmer climates2.
The World Health Organization reported 0.5 million dengue cases in 2000, which increased more than tenfold to 5.2 million in 20193. 2023 recorded over 6.5 million cases4, the highest number of dengue cases in history, affecting over 80 countries. As of 30th April 2024, there were already over 7.6 million dengue cases5. The geographic range of dengue has expanded, too. In the last decade, the disease has spread to more temperate climates with the establishment of epidemic activity in parts of North America and a rise in autochthonous transmission in southern Europe6.
The dengue burden in India has followed a similar pattern to the global scenario, with a steady increase in dengue case numbers. During the 2000–2017, dengue transmission steadily increased across India compared to the 1980–1999 period7. Bihar, Karnataka, Kerala, Maharashtra, Odisha, Punjab, Rajasthan, Uttar Pradesh and West Bengal have high incidence in India. In 2023, India reported 0.28 million dengue cases8.
Dengue surveillance in India – a complex landscape
In India, dengue disease surveillance and monitoring, a key pillar to Dengue control, is managed by the Ministry of Health and Family Welfare (MoHFW)9 through the National Center for Vector Borne Disease Control (NCVBDC)/ National Centre for Disease Control (NCDC) and the Integrated Disease Surveillance Programme (IDSP). Current national policies and initiatives for managing vector-borne disease outbreaks are administered by the NCVBDC10, which conducts dengue surveillance through a network of 848 sentinel hospitals10 and 17 apex referral laboratories10. The complexity of surveillance in India is partly due to non-integrated testing channels and partly due to limited cross-functional communication between autonomous bodies assigned to manage surveillance.
Moreover, multiple dengue tests and the variability of their acceptance by the government add to the disease reporting complexity. IgM ELISA/PCR are considered gold standards in Dengue testing. However, since these tests take more than 24 hours to report, clinicians recommend a rapid antigen test that takes just 15 minutes, or a diagnosis is made based on the symptoms and platelet count. Thus, true dengue incidence will likely be exponentially higher than the reported number. Moreover, in recent years, there have been reports of multiple viral infections and cross-reactivity of the test11, leading to complications in clinical diagnosis.
Another complexity arises because the test results data from private diagnostic centres and hospitals are not integrated with government surveillance systems in the current national framework of dengue case reporting. The varying severity of the disease, testing complexities due to cross-reactivity with other viruses, delayed testing, and the circulation of different dengue serotypes together make the diagnosis, surveillance, treatment and implementation of public health programmes targeted towards dengue difficult. Thus, dengue management has to be multi-faceted, accounting for many of the above-outlined criteria. However, not all public health set-ups, especially in countries with high burdens, are mature enough to accommodate multi-factorial analysis for disease management. Thus, it is imperative to have a robust surveillance system that integrates private/public data and accounts for the different tests used to diagnose dengue. The surveillance system should also be adept enough to inform and flag anomalies to doctors who are the first responders.
Technology to the rescue
Recently, many efforts have been made to use technology to address the complexities of dengue management. For instance, leveraging AI as a strategy towards control and mitigation. Models are being built to answer questions like:
Platforms such as AeDES12 and DENGUE TRACK Beta13 can be used to track the disease. DENGUE TRACK is a dengue tracking system that is reliant on crowd surveillance as a part of its solution; AeDES, on the other hand, is a next-generation monitoring and forecasting system using calibrated ento-epidemiological models, climate models and temperature observations. These types of innovations and parallel streams of data and information will support traditional modes of dengue management. In recent years, startups have devised pioneering methods to track and deal with the disease. For instance, India Health Fund-supported Moskeet’s TrakitNow System14 is a data platform that leverages Artificial Intelligence and sensors (IoT) to track mosquito-borne diseases in high-burden communities using real-time mosquito and disease surveillance, interventions monitoring, climate, population, mobility, and environmental data. Other start-ups and companies are also focused on building better molecular tests for dengue detection.
A consortium approach to tackling dengue
Apart from these efforts, a consortium-based approach to address Dengue has also proved successful, where information and resources are being pooled. For instance, The Global Dengue & Aedes-Transmitted Diseases Consortium (GDAC)15, IDAMS – International Research Consortium on Dengue Risk Assessment, Management and Surveillance16 and the Dengue Alliance17 are contributing immensely to advancing disease research, vaccine research and disease monitoring and mitigation strategies. In India, The Alliance for Pathogen Surveillance Innovations (APSI)18 addresses dengue from multiple perspectives.
However, in spite of the plethora of work, research and effort being put at a national and international level towards dengue reduction, it is evident with the increase in cases that much still needs to be done. The need for a coordinated effort to fight and combat Dengue is becoming more and more evident. Current mitigation strategies combined with Gene drive modified mosquitoes (Target Malaria19), Wolbachia (World Mosquito Program20) and Vaccinations could be effective strategies for the future.
Dengue is a complex disease with increasing geographical spread and infection period. Traditional methods of disease mitigation need to evolve to accommodate new technologies, focus on capacity building of the health workforce and strengthen the current systems. Disease management should have a multi-sectoral approach. Working across geographical boundaries and exchanging best practices would be ideal to save time, effort and lives. Overall, the key to solving the dengue conundrum will be implementing multi-faceted programmes combining traditional surveillance with evolving mitigation strategies. This approach to the disease would support an overburdened surveillance struggling to cope with the increase in disease spread.
Priyanki Shah is passionate and intrigued by public health. She has spent the last 15 years traversing between the private and public healthcare sectors. She thrives in supporting and ideating large-scale public health projects. She has experience in developing and enhancing infectious disease-focused public health initiatives. Her experience represents a variety of health ecosystem sectors, including the government, academia, start-ups, philanthropic organizations, pharmaceutical businesses, market research firms, and clinical research organizations. She has worked as a consultant with the World Bank and Clinton Health Access Initiatives. Her wide range of exposure has allowed her to view public health and the health ecosystem from various angles, which has led to her gaining extensive knowledge in the field. She is excellent at assembling diverse stakeholders and creating coalitions around shared objectives. She holds a Master’s in Molecular Medicine from the University of Sheffield and another Master’s in Microbiology from Bangalore University and is a qualified project manager.
India Health Fund is registered as Confluence for Health Action and Transformation Foundation (CHATF), a Section 8
charitable company incorporated in India, supported by the Tata Trusts.
