Japanese Encephalitis: Estimating Future Trends in Asia

Julia Metelka; Colin Robertson; Craig Stephen; Julia Metelka; Colin Robertson; Craig Stephen

doi:10.3934/publichealth.2015.4.601

AIMS Public Health

2015, Volume 2, Issue 4: 601-615. doi: 10.3934/publichealth.2015.4.601

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Research article Special Issues

Japanese Encephalitis: Estimating Future Trends in Asia

1.
Department of Geography & Environmental Studies, Wilfrid Laurier University, Waterloo, ON, Canada;
2.
Canadian Wildlife Health Cooperative, Saskatoon, Canada

Received: 25 February 2015 Accepted: 17 August 2015 Published: 31 August 2015

Limited surveillance programs and lack of diagnostic laboratory testing capacity in many low and middle income Asian countries have made it difficult to validate epidemiological patterns and anticipate future changes in disease risk. In this study, we consider the case of Japanese Encephalitis in Asia and examine how populations of human hosts and animal reservoirs are expected to change over the next three decades. Growth was modelled at the sub-national level for rural and urban areas to estimate where high-density, susceptible populations will potentially overlap with populations of the virus' amplifying host. High-risk areas based on these projections were compared to the current distribution of Japanese Encephalitis, and known immunization activities in order to identify areas of highest priority for concern. Results indicated that mapping JE risk factors at the sub-national level is an effective way to contextualize and supplement JE surveillance data. New patterns of risk factor change occurring in Southeast Asia were identified, including around major urban areas experiencing both urbanization and growth in pig populations. A hotspot analysis of pig-to-population ratio found a significant spatial cluster extending northward through Southeast Asia and interior China. Mapping forecasted changes in risk factors for JE highlights regions vulnerable to emerging zoonoses and may be an important tool for developing effecting transnational health policies.
- Japanese encephalitis,
- Asia,
- disease estimation,
- forecasting,
- population change,
- disease risk mapping
Citation: Julia Metelka, Colin Robertson, Craig Stephen. Japanese Encephalitis: Estimating Future Trends in Asia[J]. AIMS Public Health, 2015, 2(4): 601-615. doi: 10.3934/publichealth.2015.4.601

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Abstract

Limited surveillance programs and lack of diagnostic laboratory testing capacity in many low and middle income Asian countries have made it difficult to validate epidemiological patterns and anticipate future changes in disease risk. In this study, we consider the case of Japanese Encephalitis in Asia and examine how populations of human hosts and animal reservoirs are expected to change over the next three decades. Growth was modelled at the sub-national level for rural and urban areas to estimate where high-density, susceptible populations will potentially overlap with populations of the virus' amplifying host. High-risk areas based on these projections were compared to the current distribution of Japanese Encephalitis, and known immunization activities in order to identify areas of highest priority for concern. Results indicated that mapping JE risk factors at the sub-national level is an effective way to contextualize and supplement JE surveillance data. New patterns of risk factor change occurring in Southeast Asia were identified, including around major urban areas experiencing both urbanization and growth in pig populations. A hotspot analysis of pig-to-population ratio found a significant spatial cluster extending northward through Southeast Asia and interior China. Mapping forecasted changes in risk factors for JE highlights regions vulnerable to emerging zoonoses and may be an important tool for developing effecting transnational health policies.

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