Dengue Fever

Dengue is caused by a virus of the genus Flavivirus, within the family Flaviviridae. It is spread by the bite of an infected Aedes spp. mosquito, which predominantly feed during daytime hours.

There are four distinct serotypes of dengue virus: DENV-1, DENV-2, DENV-3 and DENV-4. All have the potential to cause severe dengue, formerly known as dengue haemorrhagic fever (DHF). Severe dengue is more likely if a person has had a previous dengue infection.

According to the World Health Organization (WHO), the number of dengue cases reported worldwide has grown dramatically in recent decades. In 2000, there were 505,430 dengue cases reported to WHO, compared with 5.2 million in 2019 [1]. Factors associated with increasing risk of spread of dengue epidemic include climate change leading to increasing temperatures, high rainfall and humidity [2]. Other factors include the increased movement of people and goods, urbanisation and pressure on water and sanitation [3].

Under reporting, misclassification of disease and the practice of reporting confirmed cases only, means the global burden of disease is likely to be far greater: approximately half of the world’s population is at risk, and it is therefore estimated that the likely incidence of disease is between 100-400 million infections each year [1].