Assessing dengue control in Tokyo, 2014

PLoS Negl Trop Dis. 2019 Jun 21;13(6):e0007468. doi: 10.1371/journal.pntd.0007468. eCollection 2019 Jun.


Background: In summer 2014, an autochthonous outbreak of dengue occurred in Tokyo, Japan, in which Yoyogi Park acted as the focal area of transmission. Recognizing the outbreak, concerted efforts were made to control viral spread, which included mosquito control, public announcement of the outbreak, and a total ban on entering the park. We sought to assess the effectiveness of these control measures.

Methodology/principal findings: We used a mathematical model to describe the transmission dynamics. Using dates of exposure and illness onset, we categorized cases into three groups according to the availability of these datasets. The infection process was parametrically modeled by generation, and convolution of the infection process and the incubation period was fitted to the data. By estimating the effective reproduction number, we determined that the effect of dengue risk communication together with mosquito control from 28 August 2014 was insufficiently large to lower the reproduction number to below 1. However, once Yoyogi Park was closed on 4 September, the value of the effective reproduction number began to fall below 1, and the associated relative reduction in the effective reproduction number was estimated to be 20%-60%. The mean incubation period was an estimated 5.8 days.

Conclusions/significance: Regardless of the assumed number of generations of cases, the combined effect of mosquito control, risk communication, and park closure appeared to be successful in interrupting the chain of dengue transmission in Tokyo.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Basic Reproduction Number
  • Communicable Disease Control / methods*
  • Communicable Disease Control / organization & administration*
  • Dengue / epidemiology*
  • Dengue / prevention & control*
  • Disease Transmission, Infectious / prevention & control*
  • Female
  • Health Services Research*
  • Humans
  • Models, Theoretical
  • Tokyo / epidemiology

Grants and funding

BY received financial support from China Scholarship Council. HL received funding from the JSPS Program for Advancing Strategic International Networks to Accelerate the Circulation of Talented Researchers. HN received funding from the Japan Agency for Medical Research and Development (AMED) [grant number JP18fk0108050]; the Japan Society for the Promotion of Science (JSPS) KAKENHI [grant numbers, HN: 16KT0130, 16K15356, 17H04701, 17H05808, and 18H04895], [grant number HL: 18H06385), the Inamori Foundation, and the Japan Science and Technology Agency (JST) CREST program [grant number JPMJCR1413]. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.