Dengue virus is the cause of dengue fever. It is a mosquito-borne, single positive-stranded RNA virus of the family Flaviviridae genus Flavivirus. Five serotypes of the virus have been found, all of which can cause the full spectrum of disease. Nevertheless, scientists’ understanding of dengue virus may be simplistic, as rather than distinct antigenic groups, a continuum appears to exist.
This same study identified 47 strains of the virus. Additionally, co-infection with and lack of rapid tests for zika virus and chikungunya complicate matters in real-world infections.
The incidence has grown dramatically around the world in recent decades. A vast majority of cases are asymptomatic and hence the actual numbers of dengue cases are under reported and many cases are misclassified.
One estimate indicates 390 million infections per year, of which 96 million manifest clinically (with any severity of disease). Another study, of the prevalence of dengue, estimates that 3.9 billion people, in 128 countries, are at risk of infection with viruses.