title: Predicting local dengue transmission in Guangzhou, China, through the influence of imported cases, mosquito density and climate variability.
abstract: BACKGROUND
  Each year there are approximately 390 million dengue infections worldwide. Weather variables have a significant impact on the transmission of Dengue Fever (DF), a mosquito borne viral disease. DF in mainland China is characterized as an imported disease. Hence it is necessary to explore the roles of imported cases, mosquito density and climate variability in dengue transmission in China. The study was to identify the relationship between dengue occurrence and possible risk factors and to develop a predicting model for dengue's control and prevention purpose.
  
  
  RESULTS
  Three traditional suburbs and one district with an international airport in Guangzhou city were selected as the study areas. Autocorrelation and cross-correlation analysis were used to perform univariate analysis to identify possible risk factors, with relevant lagged effects, associated with local dengue cases. Principal component analysis (PCA) was applied to extract principal components and PCA score was used to represent the original variables to reduce multi-collinearity. Combining the univariate analysis and prior knowledge, time-series Poisson regression analysis was conducted to quantify the relationship between weather variables, Breteau Index, imported DF cases and the local dengue transmission in Guangzhou, China. The goodness-of-fit of the constructed model was determined by pseudo-R2, Akaike information criterion (AIC) and residual test. There were a total of 707 notified local DF cases from March 2006 to December 2012, with a seasonal distribution from August to November. There were a total of 65 notified imported DF cases from 20 countries, with forty-six cases (70.8%) imported from Southeast Asia. The model showed that local DF cases were positively associated with mosquito density, imported cases, temperature, precipitation, vapour pressure and minimum relative humidity, whilst being negatively associated with air pressure, with different time lags.
  
  
  CONCLUSIONS
  Imported DF cases and mosquito density play a critical role in local DF transmission, together with weather variables. The establishment of an early warning system, using existing surveillance datasets will help to control and prevent dengue in Guangzhou, China.
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing, China; Key Laboratory of Surveillance and Early-Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China; WHO Collaborating Centre for Vector Surveillance and Management, Changping, Beijing, China; Shandong University Climate Change and Health Center, Jinan, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China.
authors.forename: Shaowei
authors.initials: S
authors.lastname: Sang
authors.affiliation: Key Laboratory of Surveillance and Early-Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Wenwu
authors.initials: W
authors.lastname: Yin
authors.affiliation: School of Population Health, University of Adelaide, Adelaide, South Australia, Australia.
authors.forename: Peng
authors.initials: P
authors.lastname: Bi
authors.affiliation: Key Laboratory of Surveillance and Early-Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Honglong
authors.initials: H
authors.lastname: Zhang
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing, China; Department of Preventive Medicine, College of Basic Medical Sciences, Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China; Shandong University Climate Change and Health Center, Jinan, China.
authors.forename: Chenggang
authors.initials: C
authors.lastname: Wang
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing, China; Key Laboratory of Surveillance and Early-Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China; WHO Collaborating Centre for Vector Surveillance and Management, Changping, Beijing, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China.
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing, China; Xiamen Entry-Exit Inspection and Quarantine Bureau, Xiamen, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Chen
authors.affiliation: Key Laboratory of Surveillance and Early-Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Weizhong
authors.initials: W
authors.lastname: Yang
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing, China; Key Laboratory of Surveillance and Early-Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China; WHO Collaborating Centre for Vector Surveillance and Management, Changping, Beijing, China; Centre for Environment and Population Health, Nathan Campus, Griffith University, Nathan, Queensland, Australia; Shandong University Climate Change and Health Center, Jinan, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China.
authors.forename: Qiyong
authors.initials: Q
authors.lastname: Liu
mesh_terms: D000818:Animals; D002681:China / Q000453:epidemiology; D002980:Climate; D009033:Culicidae / Q000502:physiology*; D003715:Dengue / Q000453:epidemiology / Q000635:transmission*; D004196:Disease Outbreaks / Q000517:prevention & control; D005544:Forecasting; D005843:Geography; D006801:Humans; D006813:Humidity; D011156:Population Density; D025341:Principal Component Analysis; D012307:Risk Factors; D013696:Temperature