The Spatial Heterogeneity between Japanese Encephalitis Incidence Distribution and Environmental Variables in Nepal

2011

Environmental Factors Affecting Japanese Encephalitis in Nepal

Sample size: 669 publication 10 minutes Evidence: moderate

Author Information

Author(s): Daniel E. Impoinvil, Tom Solomon, W. William Schluter, Ajit Rayamajhi, Ram Padarath Bichha, Geeta Shakya, Cyril Caminade, Matthew Baylis

Primary Institution: University of Liverpool

Hypothesis

The environmental drivers of JEV transmission were the same before and after the 2005 epidemic.

Conclusion

The spatial pattern of JE cases during the 2005 epidemic in Nepal was significantly associated with low precipitation and the percentage of irrigated land.

Supporting Evidence

JE cases clustered in the terai prior to 2006 where it seemed to shift to the Kathmandu region in subsequent years.
JE incidence during the 2005 epidemic had a stronger association with May mean monthly temperature and April mean monthly total precipitation.
A significant negative relationship was found between JE incidence and April precipitation.
A significant positive relationship was found between JE incidence and percentage of irrigated land.

Takeaway

This study looked at how weather and land use affect the spread of a disease called Japanese Encephalitis in Nepal, finding that less rain and more irrigated land can lead to more cases.

Methodology

An ecological study using district-level data on JE cases and environmental variables analyzed through Local Indicators of Spatial Association (LISA) and spatial lag regression models.