The role of environmental factors in the spatial distribution of Japanese encephalitis in mainland China

Abstract

Japanese encephalitis (JE) is the most common cause of viral encephalitis and an important public health concern in the Asia-Pacific region, particularly in China where 50% of global cases are notified. To explore the association between environmental factors and human JE cases and identify the high risk areas for JE transmission in China, we used annual notified data on JE cases at the center of administrative township and environmental variables with a pixel resolution of 1 km×1 km from 2005 to 2011 to construct models using ecological niche modeling (ENM) approaches based on maximum entropy. These models were then validated by overlaying reported human JE case localities from 2006 to 2012 onto each prediction map. ENMs had good discriminatory ability with the area under the curve (AUC) of the receiver operating curve (ROC) of 0.82-0.91, and low extrinsic omission rate of 5.44-7.42%. Resulting maps showed JE being presented extensively throughout southwestern and central China, with local spatial variations in probability influenced by minimum temperatures, human population density, mean temperatures, and elevation, with contribution of 17.94%-38.37%, 15.47%-21.82%, 3.86%-21.22%, and 12.05%-16.02%, respectively. Approximately 60% of JE cases occurred in predicted high risk areas, which covered less than 6% of areas in mainland China. Our findings will help inform optimal geographical allocation of the limited resources available for JE prevention and control in China, find hidden high-risk areas, and increase the effectiveness of public health interventions against JE transmission.

Clinical characteristics and outcome of clinically diagnosed viral encephalitis in southwest China

“…In addition, research shows that no more than 30-40 % of encephalitis cases can be pathogenically diagnosed, of which Japanese encephalitis (JE) is the most common cause and 50 % of global cases are notified in China [8,20]. And more than half of pathogenically diagnosed viral encephalitis have a poor prognosis [21].…”

Diagnostic approaches to malaria in Zambia, 2009-2014

“…In addition, both timely and accurate diagnosis as well as the benefits of testing before commencement of malaria treatment should be emphasized. Regularly updated malaria risk maps (Haque et al, 2010b;Reid et al, 2010Reid et al, , 2012Haque et al, 2011;Wang et al, 2014) can help the NMCC to monitor progress and mobilize resources. Distance, population density, treatment seeking behavior and other health facilities should be considered (Ahmed et al, 2009;Haque et al, 2012;Simon et al, 2013).…”

Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): Japanese encephalitis (JE)

“…Absolute humidity is related to longevity, mating, dispersal, and feeding behaviour of mosquitoes. Temperatures within the range 22-34°C increases mosquito density, decreases larval development time and reduces the extrinsic incubation period of the virus in mosquito vectors, affecting potential JEV transmission (Wang et al, 2014;Tian et al, 2015).…”