India's Growing Dengue Burden: The Need for Year-Round Vigilance, Prevention, and Public Health Preparedness

Dengue is developing as one of India's most serious and complex public health issues. Once believed to be largely a seasonal urban virus linked to monsoon outbreaks, dengue is now a year-round danger that affects both urban and semi-urban residents nationwide. With rising incidence, expanding geographic spread in a vast country, and changing transmission dynamics brought on by rapid urbanization, climate variability, population density, environmental changes, and vector adaptation, recent data indicate that India is substantially contributing to the global dengue burden (1,2).

Rising Dengue Burden in India in Recent Decades

According to the Global Burden of Disease (GBD) report, dengue incidence and mortality have increased dramatically over the last three decades, with India maintaining one of Asia's highest burden countries (1). Recent state-level epidemiological research in India revealed substantial geographic expansions, with endemic areas such as Tamil Nadu, Maharashtra, Kerala, and Delhi continuing to report high case counts (3). However, new hotspots are being identified in northeastern states and previously low-incidence areas. According to newer data, dengue incidence increased by 2,105% in Assam and 1,113% in Manipur between 2021 and 2024, indicating that dengue transmission is spreading geographically (2,3).

Changing Transmission Dynamics: Impact of Urbanization & Climate Change

Inadequate water management, poor sanitation, rapid and unplanned urbanization, and climate change are all contributing to the spread of dengue in India by fostering Aedes aegyti mosquito breeding conditions and extending vector habitats outside of historically endemic areas (4).

High population density and increasing urban settlements continue to promote mosquito breeding and dengue transmission. Rapid urbanisation and suboptimal infrastructure often lead to with inadequate water supply leading to improper storage, water-filled potholes, poor drainage and sanitation systems, fostering conditions for mosquito breeding and dengue transmission.

Climate variability is having an increasing impact on dengue epidemics in India. Rising temperatures, shifting rainfall patterns, and rising humidity provide ideal circumstances for mosquito breeding and extended transmission seasons. A recent climate-dengue modelling study from Pune found significant relationships between temperature, rainfall variability, humidity, and dengue dynamics, implying a large increase in dengue-related mortality (5). The changing epidemiology is also becoming evident at the city level. Recent reports from Ahmedabad indicate that dengue is no longer restricted to the monsoon and post-monsoon months but is increasingly being reported throughout the year, reflecting a shift from seasonal outbreaks to more sustained transmission patterns. Urbanisation, changing climate conditions, and persistent breeding habitats are believed to be contributing to this trend (6,7)

A recent India report highlighted that climate-related shifts in temperature and rainfall patterns are increasing the transmission of vector-borne diseases such as dengue. It reported that the transmission potential for dengue transmitted by Aedes albopictus increased by 85%, with an average R₀ (Reproduction number- a measure of how many new infections one case can generate) of 1.6 during 2014–2023 (8).

Dengue Beyond the Monsoon: Emerging as a Year-Round Public Health Challenge

In India, dengue is spreading beyond its typical monsoon and post-monsoon cycle. Dengue cases were found in pre-monsoon, monsoon, and post-monsoon periods in new tertiary conducted care research from India, suggesting that the disease is still spreading beyond the busiest rainy months (9). Delhi's high-resolution spatial modeling also showed that warmer, densely populated metropolitan areas continue to spread dengue between outbreaks, especially in places where mosquito carrying capacity is favourable (10). Climate-based vector dispersal studies suggest that Aedes aegypti and Aedes albopictus will become more adaptable in diverse Indian geographies as climatic conditions change (11). All of these results point to dengue's epidemiological behavioural transition from a seasonal outbreak to a more widespread year-round public health concern.

Dengue - Growing Brunt on Indian Healthcare Systems

Dengue epidemics have put a considerable strain on Indian healthcare systems, increasing outpatient visits, hospital admissions, laboratory tests, transfusion needs, and critical care demands. A tertiary-care study in eastern India involving 718 admitted dengue patients discovered that 371 (51.7%) required ICU admission, 224 (31.2%) had bleeding manifestations, 185 (25.8%) developed kidney involvement, and 25 (3.5%) died during hospitalization, demonstrating the importance of inpatient care intensity needs during outbreaks though India’s CFR remains low-0.13% in 2024 (9,10).

Figure: Dengue Beyond the Monsoon

Current Gaps in Vector Control and Community Participation

Sustained dengue control in India will depend on continuous vector surveillance, source reduction, and strong community participation. Recent studies from Delhi identified poor water storage practices, inadequate waste disposal, drainage problems, and nearby construction sites as major factors promoting Aedes mosquito breeding and dengue transmission (16). Community-based research from Pune found that awareness regarding mosquito breeding sites was low, with only 26.1% of participants correctly identifying indoor breeding sources and 38.1% recognizing outdoor breeding sites (17).

Strengthening Surveillance and Public Health Preparedness: Multi-Level Collaboration Needs

"Strengthening dengue surveillance and public health preparedness requires integrated systems that combine timely case detection, laboratory confirmation, vector monitoring, and rapid outbreak response. Improving data quality, standardizing reporting mechanisms, and enhancing coordination between healthcare facilities and public health authorities can facilitate early outbreak detection and targeted interventions, ultimately reducing dengue transmission and disease burden (18)."

Table 1. Collaborative Roles of Key Stakeholders in Dengue Prevention and Control

Final Words

Dengue in India seems no longer just a seasonal threat but a year-round public health challenge driven by urbanization, climate change, and expanding vector habitats. Strengthening surveillance, vector control, early diagnosis, healthcare preparedness, and community participation is essential to reduce transmission and prevent outbreaks. As dengue continues to expand across India, year-round vigilance is no longer optional, but is a public health necessity.

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Document number : C-ANPROM/IN/NON/0043; Date of Preparation: June 2026