Spatiotemporal characteristics and primary influencing factors of typical dengue fever epidemics in China

Abstract

Background Dengue fever (DF) is a common mosquito-borne viral infectious disease in the world, and increasingly severe DF epidemics in China have seriously affected people’s health in recent years. Thus, investigating spatiotemporal patterns and potential influencing factors of DF epidemics in typical regions is critical to consolidate effective prevention and control measures for these regional epidemics. Methods A generalized additive model (GAM) was used to identify potential contributing factors that influence spatiotemporal epidemic patterns in typical DF epidemic regions of China (e.g., the Pearl River Delta [PRD] and the Border of Yunnan and Myanmar [BYM]). In terms of influencing factors, environmental factors including the normalized difference vegetation index (NDVI), temperature, precipitation, and humidity, in conjunction with socioeconomic factors, such as population density (Pop), road density, land-use, and gross domestic product, were employed. Results DF epidemics in the PRD and BYM exhibit prominent spatial variations at 4 km and 3 km grid scales, characterized by significant spatial clustering over the Guangzhou-Foshan, Dehong, and Xishuangbanna areas. The GAM that integrated the Pop-urban land ratio (ULR)-NDVI-humidity-temperature factors for the PRD and the ULR-Road density-NDVI-temperature-water land ratio-precipitation factors for the BYM performed well in terms of overall accuracy, with Akaike Information Criterion values of 61 859.89 and 826.65, explaining a total variance of 83.4 and 97.3%, respectively. As indicated, socioeconomic factors have a stronger influence on DF epidemics than environmental factors in the study area. Among these factors, Pop (PRD) and ULR (BYM) were the socioeconomic factors explaining the largest variance in regional epidemics, whereas NDVI was the environmental factor explaining the largest variance in both regions. In addition, the common factors (ULR, NDVI, and temperature) in these two regions exhibited different effects on regional epidemics. Conclusions The spatiotemporal patterns of DF in the PRD and BYM are influenced by environmental and socioeconomic factors, the socioeconomic factors may play a significant role in DF epidemics in cases where environmental factors are suitable and differ only slightly throughout an area. Thus, prevention and control resources should be fully allocated by referring to the spatial patterns of primary influencing factors to better consolidate the prevention and control measures for DF epidemics. Electronic supplementary material The online version of this article (10.1186/s40249-019-0533-9) contains supplementary material, which is available to authorized users.

Determination of Factors Affecting Dengue Occurrence in Representative Areas of China: A Principal Component Regression Analysis

“…In particular, Xishuangbanna belongs to the tropical rain forest area, and the suitable meteorological conditions are more conducive to Aedes mosquito breeding, favoring the local outbreak of dengue. The findings were consistent with those in the previous investigation conducted in the border areas of Yunnan and Myanmar [BYM]) ( 7 ). Due to the relatively little evidence in Xishuangbanna prefecture of Yunnan, more future studies are warranted to further explore the key factors driving the local outbreak of dengue in this area.…”

“…At present, many studies focused on the influencing factors relevant to the local transmission, even outbreaks of dengue in representative regions of mainland China, including the two cities or regions in this study ( 7 ). Usually, dengue outbreaks are the consequence of the combination of many favorable conditions ( 6 , 8 ).…”

“…Globally, the incidence of dengue has increased 30-fold over the past 50 years ( 1 ). Driven by climatic and environmental changes ( 2 ), globalization, urbanization ( 3 , 4 ), vector activity, and human behavior change ( 5 ), or the combination of these favorable conditions ( 6 , 7 ), dengue outbreaks have been continuously occurring in southern China such as Guangdong ( 8 – 13 ) and Yunnan ( 14 – 17 ) since 2013, which has posed an important public health threat in China ( 18 – 23 ).…”

The driver of dengue fever incidence in two high-risk areas of China: A comparative study

“…Dengue fever is endemic in many tropical and subtropical regions in the world, especially in Southeast Asia, southern Africa and the Western Pacific 2 . In mainland of China, dengue fever was a localized epidemic disease caused by imported cases with several outbreaks of dengue fever in southern provinces since 2012, especially in Guangdong 3–5 and Yunnan provinces 6–8 . After 1949, the first large-scale outbreak of dengue fever occurred in Foshan city, Guangdong province in 1978 followed by three major outbreaks in the province in 1980, 1981 and 2014 6,9 with more than 10,000 cases of dengue fever for every year, including more than 45,000 cases of dengue fever in 2014 10–13 .…”

Urban mosquito management administration: Mosquito (Diptera: Culicidae) habitat surveillance and questionnaire survey in Wuhan, Central China

“…Administration is the weak link of urban integrated mosquito management in the city [42]. To combat mosquito-borne diseases [43,44] and to improve the quality of life of residents, we recommend that PHCS honestly reveals defects in urban mosquito management and seriously takes those exposed defects. The PHCS should strengthen PHC activities by strict adherence to NSC standards.…”