Japanese encephalitis

Infected mosquitoes of the species Culex tritaeniorhynchus spread Japanese encephalitis virus (JEV).^[1] JEV has multiple vertebrate hosts, such as pigs and water birds, and is consequently spread in rice paddy fields and rural areas where human-pig interactions are high.

Through large vaccination campaigns, the number of cases has reduced from 1678 in 2018 to 804 in 2025. The number of JE deaths has reduced from 182 in 2018 to 84 in 2025.^[2] However, the disease has a high fatality rate of 20-30%, and 30-50% of the survivors develop irreversible neurological and psychiatric complications.^[3]

How we address this challenge

We build mathematical models to understand disease progression and epidemiology for effective vaccination programmes.

• Understand behaviour, distribution, and prevalence of JEV strains in endemic regions.
• Analyse transmission dynamics to determine the trajectory, size, peak, and duration of an epidemic.
• Assess the impact of control strategies, resource allocation, and the availability of treatments or vaccinations.

Ongoing work

We have modelled the transmission dynamics of JEV to determine the trajectory, size, peak, and duration of an epidemic so as to be able to assist decision-makers in analysing future scenarios, including the impact of control strategies, resource allocation, and the availability of treatments or vaccinations. We are also fine-tuning the mathematical model formulation for the estimation of disease-free equilibrium points and endemic equilibrium points.

Publications

• Thippeswamy H, KP Suresh, Pandey RK, Sekar YS, Ramesh V, Kamble N, Palavesam A, Patil SS, Hiremath J. An Integrated Computational Approach to Predict and Characterize Emerging Mutations in the Japanese Encephalitis Virus Envelope Protein. 2026. Preprint

References

1. Kulkarni, R., Sapkal, G. N., Kaushal, H., & Mourya, D. T. (2018). Japanese encephalitis: A brief review on Indian perspectives. The Open Virology Journal, 12, 121-130. https://doi.org/10.2174/1874357901812010121
2. National Centre for Vector Borne Diseases Control. (n.d.). Japanese encephalitis data.
   https://ncvbdc.mohfw.gov.in/index1.php?lang=1&level=2&sublinkid=5917&lid=4001
3. Siva, N., Samantaray, K. K., Tripathy, P., et al. (2026). Japanese encephalitis among children in India: Proportion of cases, case fatality, and epidemiological patterns - A systematic review and meta-analysis. BMC Public Health, 26, 1601.
   https://doi.org/10.1186/s12889-026-27237-z