No abstract

Culex tritaeniorhynchus is an important vector that transmits a variety of human and animal diseases. Japanese encephalitis (JE), an endemic disease in the Asia-Pacific region, is primarily transmitted by Cx. tritaeniorhynchus. Insufficient monitoring of vector mosquitoes has led to a poor understanding of the distribution of Cx. tritaeniorhynchus in China. To delineate the habitat of Cx. tritaeniorhynchus and any host and environmental factors that affect its distribution, we used a maximum entropy modeling method to predict its distribution in China. Our models provided high resolution predictions on the potential distribution of Cx. tritaeniorhynchus. The predicted suitable habitats of the JE vector were correlated with areas of high JE incidence in parts of China. Factors driving the distribution of Cx. tritaeniorhynchus in China were also revealed by our models. Furthermore, human population density and the maximum NDVI were the most important predictors in our models. Bioclimate factors and elevation also significantly impacted the distribution of Cx. tritaeniorhynchus. Our findings may serve as a reference for vector and disease control.

BACKGROUNDIntense studies have been carried out on the effects of climate change on vector‐borne diseases and vectors. Culex pipiens pallens and Culex pipiens quinquefasciatus are two medically concerned mosquito species in temperate and tropical areas, which serve as important disease‐transmitting pests of a variety of diseases. The ongoing geographical expansion of these mosquitoes has brought an increasing threat to public health.RESULTSBased on mosquito occurrence records and high‐resolution environmental layers, an ecological niche model was established to model their current and future potential distribution in China. Our model showed that the current suitable area for Cx. p. pallens is distributed in the central, eastern and northern parts of China, while Cx. p. quinquefasciatus is distributed in vast areas in southern China. Under future climate change scenarios, both species are predicted to expand their range to varying degrees and RCP 8.5 provides the largest expansion. Northward core shifts will occur in ranges of both species. Environmental variables which have significant impact on the distribution of mosquitoes were also revealed by our model.CONCLUSIONSevere habitat expansion of vectors is likely to occur in the future 21st century. Our models mapped the high‐risk areas and risk factors which needs to be paid attention. The results of our study can be referenced in further ecological surveys and will guide the development of strategies for the prevention and control of vector‐borne diseases. © 2020 Society of Chemical Industry

BACKGROUND: Aedes aegypti is one of the most important mosquito species and is a common disease-transmitting pest in tropical areas. Various infectious arbovirus diseases can be transmitted by Ae. aegypti. With ongoing global climate change, we are facing an increasing public health threat from the rapid spread of disease vectors into wider geographical areas. To better understand the current ecological niche range and possible future expansion of Ae. aegypti, an ecological niche modelling approach was adopted to predict its current and future potential habitat in Taiwan, China. 30 arcsec (approx. 1 × 1 km) were made by our model. Ae. aegypti was predicted to expand its habitat in varying degrees out of its current niche range under different climate scenarios for the future 21st century. Winter temperature and dry season precipitation were considered as important predictors among climate variables. Croplands, pasture, forested lands and urban lands were important land-use variables. RESULTS: Based on observed occurrence records and environmental layers reflecting climate and land-use conditions, predictions with a high resolution of CONCLUSION:Ae. aegypti is expected to establish new habitats out of its current niche range under the trend of global climate change. The extent of habitat expansion varies under different climate scenarios. Appropriate measures should be taken to prevent its expansion to a broader scale. Our study has important strategic implications for mosquito surveillance and the prevention and control of mosquito-borne diseases.

Bluetongue (BT) is a non-contagious disease affecting domestic and wild ruminants. Outbreaks of BT can cause serious economic losses. To investigate the distribution characteristics of bluetongue virus (BTV), two large-scale censuses of BTV prevalence in Xinjiang, China were collected. Spatial autocorrelation analysis, including global spatial autocorrelation and local spatial autocorrelation, was performed. Risk areas for BTV occurrence in Xinjiang were detected using the presence-only maximum entropy model. The global spatial autocorrelation of BTV distribution in Xinjiang in 2012 showed a random pattern. In contrast, the spatial distribution of BTV from 2014 to 2015 was significantly clustered. The hotspot areas for BTV infection included Balikun County (p < 0.05), Yiwu County (p < 0.05) and Hami City (p < 0.05) in 2012. These three regions were also hotspot areas during 2014 and 2015. Sheep distribution (25.6% contribution), precipitation seasonality (22.1% contribution) and mean diurnal range (16.2% contribution) were identified as the most important predictors for BTV occurrence in Xinjiang. This study demonstrated the presence of high-risk areas for BTV infection in Xinjiang, which can serve as a tool to aid in the development of preventative countermeasures of BT outbreaks.

Rift Valley fever (RVF) is a vector-borne infectious disease caused by Rift Valley fever virus (RVFV, Bunyaviridae: Phlebovirus) (Pepin, Bouloy, Bird, Kemp, & Paweska, 2010). As a zoonotic disease, susceptible hosts of RVF are ruminants and humans. Abortion and high newborn mortality rates are the main clinical manifestation of RVF infection in livestock (Peyre et al., 2015). In humans, moderate