Japanese Encephalitis: Estimating Future Trends in Asia

Area of Science:

• Epidemiology
• Veterinary Public Health
• Geographic Information Systems (GIS)

Background:

• Limited surveillance and diagnostic capacity in low- and middle-income Asian countries hinder accurate disease risk assessment.
• Understanding epidemiological patterns is crucial for anticipating future changes in infectious disease risk.

Purpose of the Study:

• To model and forecast changes in Japanese Encephalitis (JE) risk factors over the next three decades in Asia.
• To identify high-priority areas for JE surveillance and intervention by comparing projected risk factors with current JE distribution and immunization data.

Main Methods:

• Sub-national population growth modeling for rural and urban areas.
• Integration of human host and animal reservoir population changes.
• Geospatial analysis, including hotspot analysis of pig-to-population ratios.
• Comparison of projected risk factors with current JE distribution and immunization data.

Main Results:

• Identified new patterns of JE risk factor changes, particularly around urban areas in Southeast Asia experiencing urbanization and increased pig populations.
• Detected a significant spatial cluster of high pig-to-population ratios extending through Southeast Asia and into interior China.
• Demonstrated the effectiveness of sub-national risk factor mapping for contextualizing and supplementing JE surveillance data.

Conclusions:

• Sub-national mapping of forecasted JE risk factors is an effective tool for identifying vulnerable regions.
• Findings highlight regions susceptible to emerging zoonotic diseases, informing transnational health policy development.
• Proactive identification of high-risk areas can improve JE prevention and control strategies.