Researchers at the Indian Institute of Technology (IIT), Kharagpur, have developed CliMed, a climate-informed and spatially explicit modelling framework for dengue risk assessment over India, according to officials.
The model brings together daily climate information, land-use characteristics, human population data, settlement context and mosquito-species suitability to generate interpretable risk signals for Aedes-borne dengue transmission, they added.
ANV Satyanarayana, a professor at IIT-Kharagpur's Centre for Ocean, River, Atmosphere and Land Sciences (CORAL), explained that dengue risk is shaped by several interacting conditions.
Temperature influences mosquito biting, development, survival and the time required for the virus to become transmissible inside the mosquito, he said.
"Rainfall can create breeding opportunities, while very heavy rainfall may also disturb immature stages. Humidity affects mosquito activity and survival. Land use, settlement pattern and population distribution determine whether suitable mosquito conditions are likely to translate into meaningful human exposure.
"CliMed has been designed to read these factors together, rather than treating dengue risk as a simple statistical association between weather and reported cases," he explained.
The current implementation focuses on the two major Aedes vectors associated with dengue: Aedes aegypti, an important urban vector, and Aedes albopictus, a species often relevant in peri-urban, vegetated and comparatively cooler environments.
"By representing both species in the same modelling framework, CliMed can highlight how local climate and land use conditions may favour different components of the vector system across seasons and regions.
CliMed is intended to support preparedness by adding an environmental and biological layer to dengue risk interpretation.
"Reported case counts remain essential, but they may be delayed, unevenly recorded or influenced by testing and reporting practices.
"CliMed therefore provides a complementary view as it identifies days and locations where climate, vector ecology and exposure conditions may be becoming more favourable for transmission," he said.
The model produces more than one indicator because dengue risk has more than one dimension. A count-oriented output estimates where newly exposed people may be concentrated and is influenced by population, settlement exposure and susceptibility assumptions.
"Reading these indicators together helps distinguish likely burden concentration from ecological transmission pressure. This distinction is important for planning. In a densely populated area, even moderate transmission suitability may correspond to a larger population-linked burden.
"In another location, the population-linked count may remain comparatively stable while climate-vector pressure increases, indicating a need for closer surveillance, vector-control readiness and local validation," he said.
The framework can be applied to national, state, district, campus or custom study areas when appropriate gridded inputs and boundaries are available, according to Satyanarayana.
