Bluetongue Risk Map for Vaccination and Surveillance Strategies in India

Area of Science:

• Veterinary Epidemiology
• Remote Sensing Applications
• Disease Ecology

Background:

• Bluetongue virus (BTV) causes significant economic losses in ruminants globally.
• BTV is endemic to South India, with frequent outbreaks impacting sheep and food security.
• Complex epidemiology involves diverse hosts, multiple biting midge vectors (Culicoides spp.), and numerous BTV serotypes.

Purpose of the Study:

• To develop a predictive model for bluetongue (BT) distribution in South India.
• To identify key environmental and remote sensing variables influencing BTV presence.
• To create risk maps for disease management and surveillance.

Main Methods:

• Utilized bluetongue presence data (1997-2011) from South India.
• Employed non-linear discriminant analysis (NLDA) with remotely sensed variables.
• Incorporated temporal Fourier transformed variables, including land surface temperature (LST) and Normalized Difference Vegetation Index (NDVI).

Main Results:

• Top predictors of BT distribution included thermal metrics (LST, MIR) and NDVI.
• A model using pseudo-absence points demonstrated superior predictive performance.
• The model showed high correspondence with historical BTV outbreak patterns.

Conclusions:

• Remote sensing data, particularly LST and NDVI, can effectively predict BTV distribution.
• Developed risk maps can guide disease control, vaccination, and surveillance efforts.
• The findings support proactive management of bluetongue in high-risk regions.