The Epidemiological Characteristics and Dynamic Transmission of Dengue in China, 2013

Abstract

BackgroundThere was a dengue epidemic in several regions of China in 2013. No study has explored the dynamics of dengue transmission between different geographical locations with dengue outbreaks in China. The purpose of the study is to analyze the epidemiological characteristics and to explore the dynamic transmission of dengue in China, 2013.Methodology and Principal FindingsRecords of dengue cases of 2013 were obtained from the China Notifiable Disease Surveillance System. Full E-gene sequences of dengue virus detected from the outbreak regions of China were download from GenBank. Geographical Information System and heatmaps were used to describe the epidemiological characteristics. Maximum Likelihood phylogenetic and Bayesian phylogeographic analyses were conducted to explore the dengue dynamic transmission. Yunnan Province and Guangdong Province had the highest imported cases in the 2013 epidemic. In the locations with local dengue transmission, most of imported cases occurred from June to November 2013 while local dengue cases developed from July to December, 2013. There were significant variations for the incidences of dengue, in terms of age distributions, among different geographic locations. However, gender differences were identified in Guangzhou, Foshan and Xishuangbanna. DENV 1–3 were detected in all locations with the disease outbreaks. Some genotypes were detected in more than one locations and more than one genotypes have been detected in several locations. The dengue viruses introduced to outbreak areas were predominantly from Southeast Asia. In Guangdong Province, the phylogeographical results indicated that dengue viruses of DENV 1 were transmitted to neighboring cities Foshan and Zhongshan from Guangzhou city, and then transmitted to Jiangmen city. The virus in DENV 3 was introduced to Guangzhou city, Guangdong Province from Xishuangbanna prefecture, Yunnan Province.ConclusionsRepeated dengue virus introductions from Southeast Asia and subsequent domestic dengue transmission within different regions may have contributed to the dengue epidemics in China, 2013.

Age‐associated differences in clinical manifestations and laboratory parameters during a dengue virus type 4 outbreak in Argentina

“…This study reports sex‐based differences in the manifestations of DENV infection. Similar results have been reported in Mexico City,in French Caribbean islands, and in select Chinese localities . One study in Korea, a country in which DENV is almost exclusively imported by travelers, found significantly higher DENV incidence in men .…”

“…Previous studies have described differences in dengue presentation based on sex . Nearly 56% of the participants in our study were female and these patients had a significantly higher rate of DWWS compared to men (43.1% vs 31.3%; Table ).…”

“…Previous studies have described differences in dengue presentation based on sex. 18,[20][21][22] Nearly 56% of the participants in our study were female and these patients had a significantly higher rate of DWWS compared to men (43.1% vs 31.3%; Table 3). Although univariate analysis showed that females had an increased risk of developing DWWS, this risk was no longer significant when adjusted for age and pre-existing immunity to DENV (Table 3).…”

“…Similar results have been reported in Mexico City, 18 in French Caribbean islands, 20 and in select Chinese localities. 21 One study in Korea, a country in which DENV is almost exclusively imported by travelers, found significantly higher DENV incidence in men. 22 Further investigation will be necessary to define whether these differences are due to physiological or to regional socio-behavioral factors.…”

Molecular characterization of the viral structural gene of the first dengue virus type 1 outbreak in Xishuangbanna, a border area of China, Burma and Laos

“…Yunnan Province is located in southwestern China and neighbors the southeast Asian countries, which are all dengue-endemic areas. Research indicates that imported DF from patients from Laos and Myanmar was the primary cause of the DF epidemic in Yunnan Province [17,18,19], whereas Chinese encouragement of implementing economic development policy with Southeast Asian will result in greater contacts between Yunnan and southeast Asian countries. This finding indicates that the dengue epidemic might become increasingly common in this Chinese border area.…”