Dengue, the most common arboviral illness transmitted worldwide, is caused by infection with 1 of the 4 serotypes of dengue virus, family Flaviviridae, genus Flavivirus (single-stranded nonsegmented RNA viruses). Dengue is transmitted by mosquitoes of the genus Aedes,which are widely distributed in subtropical and tropical areas of the world, and is classified as a major global health threat by the World Health Organization (WHO).
Initial dengue infection may be asymptomatic (50%-90%), may result in a nonspecific febrile illness, or may produce the symptom complex of classic dengue fever (DF). A small percentage of persons who have previously been infected by one dengue serotype develop bleeding and endothelial leak upon infection with another dengue serotype. This syndrome is termed dengue hemorrhagic fever (DHF), although dengue vasculopathy has been proposed as a better term, as fluid loss into tissue spaces can lead to prolonged shock and complications, including gastrointestinal bleeding, a greater fatality risk than bleeding per se. Some patients with dengue hemorrhagic fever develop shock (dengue shock syndrome [DSS]), which may cause death.
Dengue fever–like illnesses were described in Chinese medical writings dating back to 265 AD. Outbreaks of febrile illnesses compatible with dengue fever have been recorded throughout history, with the first epidemic described in 1635 in the West Indies. In 1789, Benjamin Rush, MD, published an account of a probable dengue fever epidemic that had occurred in Philadelphia in 1780. Rush coined the term breakbone fever to describe the intense symptoms reported by one of his patients. Probable outbreaks of dengue fever occurred sporadically every 10-30 years until after World War II. The socioeconomic disruptions caused by World War II resulted in increased worldwide spread of dengue viruses.
The first epidemic of dengue hemorrhagic fever was described in Manila in 1953. After that, outbreaks of dengue fever became more common. A pattern developed in which dengue fever epidemics occurred with increasing frequency and were associated with occasional dengue hemorrhagic fever cases. Subsequently, dengue hemorrhagic fever epidemics occurred every few years. Eventually, dengue hemorrhagic fever epidemics occurred yearly, with major outbreaks occurring approximately every 3 years. This pattern has repeated itself as dengue fever has spread to new regions.
Although initial epidemics were located in urban areas, increased dengue spread has involved suburban and rural locales in Asia and Latin America. The only continents that do not experience dengue transmission include Europe and Antarctica. In the 1950s, 9 countries reported dengue outbreaks; today, the geographic distribution includes more than 100 countries worldwide. Several of these countries had not previously reported dengue, and many had not reported dengue in 20 years.
Dengue transmission spread from Southeast Asia into surrounding subtropical and tropical Asian countries, southern China and southern Taiwan, the Indian subcontinent and Sri Lanka, and down the island nations of Malaysia, the Philippines, New Guinea, northeastern Australia, and several Pacific islands, including Tahiti, Palau, Tonga, and the Cook Islands. Nepal has not reported dengue transmission. Hyperendemic transmission is reported in Vietnam, Thailand, Indonesia, Pakistan, India, Malaysia, and the Philippines. Dengue continues to extend its range.
Currently, dengue hemorrhagic fever is one of the leading causes of hospitalization and death in children in many Southeast Asian countries, with Indonesia reporting the majority of dengue hemorrhagic fever cases. Of interest and significance in prevention and control, 3 surveillance studies in Asia report an increasing age among infected patients and increasing mortality rate. Since 1982 in Singapore, more than 50% of deaths have occurred in individuals older than 15 years. In Indonesia, young adults in Jakarta and provincial areas make up a larger percentage of infected patients. During the 2000 epidemic in Bangladesh, up to 82% of hospitalized patients were adults, and all deaths occurred in patients older than 5 years.
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