Dengue Fever in Asia and Africa

Abstract

Dengue is one of the most significant viral hemorrhagic fever infections worldwide. In the past 50 years the incidence of dengue fever has increased 30-fold and has expanded to areas which were previously free from the virus. An estimated 2.5 billion people live in dengue-endemic countries. Dengue virus (DENV) belongs to the family of Flaviviridae and genus Flavivirus with a single stranded positivesense RNA. The virus consists of four serotypes (DEN-1 to -4). The main route of transmission to humans is by the bites of infected Aedes mosquitoes, principally A. aegypti. Dengue has a wide spectrum of clinical symptoms, often with unpredictable clinical outcomes. After 4-10 days incubation period, infection by any of the four virus serotypes can produce a wide spectrum of illnesses, although most infections are asymptomatic or subclinical. While the infection is self-limiting in the majority of cases and patients fully recover, in a small proportion of patients the infection progresses to severe disease, mostly characterized by plasma leakage with or without hemorrhage. In its hemorrhagic form, it can be easily misdiagnosed as other hemorrhagic diseases.