The Effect of Precipitation on the Transmission of Japanese Encephalitis (JE) Virus in Nature: A Complex Effect on Antibody-Positive Rate to JE Virus in Sentinel Pigs

Abstract

Japanese encephalitis (JE) is one of the most important mosquito-borne viral diseases in Asia. Pigs are a natural host and the amplifier of JE virus. The sero-conversion rate to JE virus in sentinel pigs reflects the activity of JE virus in the region. We analyzed whether precipitation has any effect on the sero-conversion rate to JE virus in sentinel pigs. Linear regression analysis was performed to determine the correlations between the levels of precipitation and sero-conversion rates to JE virus, in the entire year and during summertime over the period of 32 years from 1969 to 2000. The levels of the annual and summertime precipitation demonstrated statistically significant positive correlations with sero-conversion rates for the whole of the country and for some regions in Japan. The levels of the summertime precipitation, on the other hand, demonstrated statistically significant inverse correlations with the sero-conversion rates in other regions. Further, the levels of precipitation during preceding 10-day periods from days 1–40 before blood collection showed inverse correlation with antibody-positive rates in some regions. The results indicate that the relationship between the annual and summertime precipitation, and the sero-conversion rate to JE virus is complex; both positive and inverse effects are demonstrated depending on the regions.

A Bibliometric Analysis of Global Research on Japanese Encephalitis From 1934 to 2020

“…The analysis of the authors helps to understand a research field more comprehensively and evaluate the contributions, research level, and the academic status of researchers in the field objectively (Podsakoff et al, 2008). Our results show that since 2010, the following JE research groups are the most representative: Solomon T. of the University of Liverpool in the UK is mainly engaged in research involving JE epidemiology (Ooi et al, 2008), pathogenesis and clinical features (Solomon and Vaughn, 2002), diagnosis and treatment methods (Solomon et al, 1998;Turtle and Solomon, 2018), immune mechanism (Turtle et al, 2016), transmission vector (Mackenzie-Impoinvil et al, 2015) and molecular epidemiology of JEV (Mohammed et al, 2011); Basu A. of the National Brain Research Center in India focuses on the pathogenesis of JEV (Mackenzie et al, 2004) and the pathology and clinical features (Ghosh and Basu, 2009) of JE; Takasaki T of the National Institute of Infectious Diseases in Japan is mainly devoted to the serological detection of the JEV antibody (Hamano et al, 2007), vaccine and immunization (Kurane and Takasaki, 2000), epidemiology survey (Kurane et al, 2013), etc. In addition, there are mainly the following groups in China: GD Liang and HY Wang of the Chinese Center for Disease Control and Prevention are mainly engaged in the analysis of the JEV genotype and molecular epidemiology (Wang et al, 2007;Pan et al, 2011;Gao et al, 2019), JE epidemiology, and disease prevention and control-related research (Yin et al, 2010;Gao et al, 2014;Wang and Liang, 2015).…”

Estimating the Distribution of Japanese Encephalitis Vectors in Australia Using Ecological Niche Modelling

“…While there is evidence mosquitoes benefit from high temperatures, too high of temperatures have been noted to be associated with increased mortality [35]. Similarly, while abundant rainfall is essential for reproduction, high levels of rainfall may washout larvae leading to a decrease in mosquito abundance [60]. Therefore, Maxent was given the option of choosing between linear and quadratic feature classes since exact temperature and precipitation values associated with the above scenarios are not well defined.…”