Climate change fuels dengue surge: New system predicts outbreaks

A dengue early warning system has been developed offering a crucial tool to preempt outbreaks and mitigate the diseasersquos rising threat amidst climate change Dengue fever one of the fastestspreading mosquitoborne diseases globally is witnessing an alarming surge closely linked to shifting climate patterns states a latest studyThe study led by Sophia Yacob and Roxy Mathew Koll from the Indian Institute of Tropical Meteorology IITM Pune projects a 1337 increase in denguerelated fatalities by 2030 and a staggering 23ndash4037 rise by 2050 if immediate interventions are not undertakenKoll said ldquo While this study is based on Punersquos climate and health data the underlying mechanismsmdashsuch as the role of temperature humidity and rainfall and there changes in causing denguemdashare broadly applicable across India Mumbais high population density and urbanization aggravates the risks We need to prepare an early warning system for Mumbai and for that we need the health data from the regionrdquoIndia contributing nearly a third of global cases faces an impending public health crisis as new research warns of a significant rise in denguerelated deathsPublished in Scientific Reports the research focuses on Pune a welldocumented dengue hotspot The findings emphasize how rising temperatures erratic monsoon rainfall and increasing humidity exacerbate the spread and lethality of dengue The study titled ldquoDengue Dynamics Predictions and Future Increase under Changing Monsoon Climate in Indiardquo calls for urgent climatesensitive health measures to mitigate the looming crisisThe study is authored by Sophia Yacob Roxy Mathew Koll Panini Dasgupta and Rajib Chattopadhyay from the Indian Institute of Tropical Meteorology Pune Raghu Murtugudde and Amir Sapkota from the University of Maryland USA Anand Karipot from the University of Pune Sujata Saunik and Kalpana Baliwant from the Government of Maharashtra Abhiyant Tiwari from NRDC India and Revati Phalkey from the University of Nottingham UKTemperaturersquos role in dengue transmissionThe study highlights how the monsoon seasonrsquos mean temperature range of 27ndash35degC in Pune fosters optimal conditions for dengue transmission These temperatures influence critical mosquitorelated factors such as lifespan egg production and the virusrsquos development within mosquitoes The analysis underscores the need for regionspecific climatedengue assessments as temperature thresholds and their relationship with other climatic factors vary across locationsRainfall patterns and dengueRainfall patterns more than total rainfall play a pivotal role in dengue spread Moderate weekly rainfall up to 150 mm significantly increases dengue mortality in Pune while heavy rains exceeding 150 mm reduce it through the ldquoflushing effectrdquo which washes away mosquito eggs and larvae The research reveals that years with low monsoon variability characterized by fewer active and break phases coincide with higher dengue cases and fatalities Conversely higher monsoon variability is associated with reduced dengue transmissionIndiarsquos Meteorological Department IMD already provides extendedrange forecasts on monsoon patterns Leveraging these forecasts could enhance dengue predictions by offering a lead time of 10ndash30 days aiding public health responsesRegional dengue early warning system A GameChangerExisting dengue warning systems in India are rudimentary focusing only on generic temperature thresholds without considering the complex interplay of rainfall humidity and temperature The new study pioneers a regionspecific dengue early warning system that integrates all potential climatebased factors to predict outbreaks over two months in advance with reasonable accuracy By using observed patterns of temperature rainfall and humidity this model offers policymakers and health authorities a valuable tool to preempt and mitigate outbreaksWhile heavy rains may temporarily disrupt mosquito breeding the overall increase in warmer days is expected to dominate future dengue trends The study emphasizes that socioeconomic factors which also influence disease transmission must be incorporated into future modelsThe effectiveness of dengue early warning systems hinges on comprehensive health data collection and sharing However significant underreporting of dengue cases in India hinders accurate analysis One study estimates that actual dengue cases are 282 times higher than the reported figuresldquoWe developed this early warning system using health data shared by Punersquos health departmentrdquo said Koll she said ldquoHowever similar efforts in other states were hampered by a lack of cooperationrdquoKoll emphasized that sharing health data alongside IMDrsquos meteorological data could enable the creation of cityspecific early warning systems for diseases like dengue malaria and chikungunyaStates such as Kerala Maharashtra Karnataka and West Bengal which bear a high dengue burden could greatly benefit from this advanced system Policymakers can leverage these insights to formulate targeted interventions allocate resources and enhance preparedness for climatesensitive diseases Koll saidWhat Experts sayKoll recounted a personal experience saying ldquoIn August 2024 my wife was hospitalized in the ICU due to dengue This personal experience highlighted the urgency of addressing dengue outbreaks Even as a climate scientist I saw firsthand how overwhelming the situation can becomerdquoSophia Yacob from IITM described the research as ldquoa significant step in understanding how climate impacts healthrdquo She explained that the model could be adapted to other regions making it a valuable tool for managing diseases like dengueSujata Saunik Chief Secretary Government of Maharashtra highlighted the collaboration stating ldquoThis partnership exemplifies how scientists health departments and governments can work together to improve public health systems and save livesrdquoAmir Sapkota from the University of Maryland emphasized ldquoOur findings lay the foundation for building climateresilient communities Anticipating disease threats ahead of time is far more effective than reacting after outbreaks occurrdquoDr Madhukar Gaikwad Unit Head of the Medicine Department at JJ Hospital and Medical College stated Dengue caused by the Aedes mosquito thrives in stagnant water Especially in the years following the pandemic cases of dengue and malaria have risen compared to five to ten years ago Climate change is undoubtedly a contributing factor to this increase Rising temperatures and increased rainfall are allowing denguecarrying mosquitoes to expand their range