title: A local outbreak of dengue caused by an imported case in Dongguan China.
abstract: BACKGROUND
  Dengue, a mosquito-borne febrile viral disease, is found in tropical and sub-tropical regions around the world. Since the first occurrence of dengue was confirmed in Guangdong, China in 1978, dengue outbreaks have been reported sequentially in different provinces in South China transmitted by peridomestic Ae. albopictus mosquitoes, diplaying Ae. aegypti, a fully domestic vector that transmits dengue worldwide. Rapid and uncontrolled urbanization is a characteristic change in developing countries, which impacts greatly on vector habitat, human lifestyle and transmission dynamics on dengue epidemics. In September 2010, an outbreak of dengue was detected in Dongguan, a city in Guangdong province characterized by its fast urbanization. An investigation was initiated to identify the cause, to describe the epidemical characteristics of the outbreak, and to implement control measures to stop the outbreak. This is the first report of dengue outbreak in Dongguan, even though dengue cases were documented before in this city.
  
  
  METHODS
  Epidemiological data were obtained from local Center of Disease Control and prevention (CDC). Laboratory tests such as real-time Reverse Transcription Polymerase Chain Reaction (RT-PCR), the virus cDNA sequencing, and Enzyme-Linked immunosorbent assay (ELISA) were employed to identify the virus infection and molecular phylogenetic analysis was performed with MEGA5. The febrile cases were reported every day by the fever surveillance system. Vector control measures including insecticidal fogging and elimination of habitats of Ae. albopictus were used to control the dengue outbreak.
  
  
  RESULTS
  The epidemiological studies results showed that this dengue outbreak was initiated by an imported case from Southeast Asia. The outbreak was characterized by 31 cases reported with an attack rate of 50.63 out of a population of 100,000. Ae. albopictus was the only vector species responsible for the outbreak. The virus cDNA sequencing analysis showed that the virus responsible for the outbreak was Dengue Virus serotype-1 (DENV-1).
  
  
  CONCLUSIONS
  Several characterized points of urbanization contributed to this outbreak of dengue in Dongguan: the residents are highly concentrated; the residents' life habits helped to form the habitats of Ae. albopictus and contributed to the high Breteau Index; the self-constructed houses lacks of mosquito prevention facilities. This report has reaffirmed the importance of a surveillance system for infectious diseases control and aroused the awareness of an imported case causing the epidemic of an infectious disease in urbanized region.
authors.affiliation: Key Laboratory of Prevention and Control for Emerging Infectious Diseases of Guangdong Higher Institutes, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong 510515, Peoples Republic of China.
authors.forename: Hong-Juan
authors.initials: HJ
authors.lastname: Peng
authors.forename: Hui-Bing
authors.initials: HB
authors.lastname: Lai
authors.forename: Qiao-Li
authors.initials: QL
authors.lastname: Zhang
authors.forename: Ba-Yi
authors.initials: BY
authors.lastname: Xu
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.forename: Wen-Hua
authors.initials: WH
authors.lastname: Liu
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.forename: Yuan-Ping
authors.initials: YP
authors.lastname: Zhou
authors.forename: Xin-Guang
authors.initials: XG
authors.lastname: Zhong
authors.forename: Shu
authors.initials: S
authors.lastname: Jiang
authors.forename: Jin-Hua
authors.initials: JH
authors.lastname: Duan
authors.forename: Gui-Yun
authors.initials: GY
authors.lastname: Yan
authors.forename: Jian-Feng
authors.initials: JF
authors.lastname: He
authors.forename: Xiao-Guang
authors.initials: XG
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D002681:China / Q000453:epidemiology; D004279:DNA, Viral / Q000302:isolation & purification; D003715:Dengue / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology / Q000635:transmission*; D004196:Disease Outbreaks / Q000517:prevention & control; D004199:Disease Vectors; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009032:Mosquito Control; D011159:Population Surveillance / Q000379:methods; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D014507:Urbanization; D055815:Young Adult
chemical_list: D004279:DNA, Viral