Basic Information on Dengue Fever

Dengue Fever

The dengue virus that causes dengue fever, the symptoms, and the number of infected people are explained.

Dengue virus symptoms and case fatality rate

Dengue fever is a mosquito-borne infectious disease. The causative virus is a dengue virus of the Flaviviridae family, and there are four related viruses: Dengue virus 1, 2, 3 and 4. It is transmitted by Aedes aegypti and Aedes albopictus and causes symptoms, such as fever, headache, and orbital pain. The fatality rate of dengue fever is not very high. However, in some cases, it can progress to a serious condition called dengue hemorrhagic fever, with a case fatality rate of 20% or more if untreated [1]. In Japan, there was a domestic epidemic in 2014, which attracted attention. The basic reproduction number (R0) at the time was 7.78 [2].

Number of people infected with dengue fever

The number of people infected with dengue fever is increasing annually, and in 2019, 4.7 million people were infected worldwide. To prevent dengue fever, it is important to prevent mosquito bites.

Dengue virus

Schematic diagram of the dengue virus, with RNA enclosed by a capsid formed by the aggregation of proteins and further enveloped by a viral envelope.


  • [1]
    WHO fact sheet “dengue and severe dengue” (2020)
    Reference URL:
  • [2]
    Hirotaka Kanuka (2016) Why mosquitoes attack people Iwanami Shoten
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