Dengue is usually transmitted by the mosquito Aedes aegypti, and rarely Aedes albopictus. The virus exists in four different types, and an infection with one type usually gives lifelong immunity to that type, but only short-term immunity to the others. There is currently no availablevaccine, but measures to reduce thehabitat and the number of mosquitoes, and limiting exposure to bites, are used to decrease the incidence of dengue.
Treatment of acute dengue is supportive, using either oral or intravenous rehydration for mild or moderate disease, and intravenous fluids andblood transfusions for more severe cases. The incidence of dengue fever has increased dramatically over the last 50 years, with around 50–100million people being infected yearly. Dengue is currently endemic in more than 110 countries. Early descriptions of the condition date from 1779, and its viral cause and the transmission were elucidated in the early 20th century. Dengue has become a worldwide problem since the Second World War.
The origins of the word "dengue" are not clear, but one theory is that it is derived fromthe Swahili phrase Ka-dinga pepo, which describes the disease as being caused by an evil spirit. The Swahili word dinga may possibly have its origin in the Spanish word dengue, meaning fastidious or careful, which would describe the gait of a person suffering the bone pain of dengue fever. However, it is possible that the use of the Spanish word derived from the similar-sounding Swahili.Slaves in the West Indies having contracted dengue were said to have the posture and gait of a dandy, and the disease was known as "dandy fever".
The term "break-bone fever" was first applied by physician and Founding Father Benjamin Rush, in a 1789 report of the 1780 epidemic in Philadelphia. In the report he uses primarily the more formal term "bilious remitting fever".[ The term denguefever came into general use only after 1828. Other historical terms include "breakheart fever" and "la dengue".Terms for severe disease include "infectious thrombocytopenic purpura" and "Philippine", "Thai", or "Singapore hemorrhagic fever".
The first record of a case of probable dengue fever is in a Chinese medical encyclopedia from the Jin Dynasty (265–420 AD) which referred to a"water poison" associated with flying insects. There have been descriptions of epidemics in the 17th century, but the most plausible early reports of dengue epidemics are from 1779 and 1780, when an epidemic swept Asia, Africa and North America. From that time until 1940, epidemics were infrequent.
In 1906, transmission by the Aedes mosquitoes was confirmed, and in 1907 dengue was thesecond disease (after yellow fever) that was shown to be caused by a virus. Further investigations by John Burton Cleland and Joseph Franklin Siler completed the basic understanding of dengue transmission.
The marked rise of spread of dengue during and after the Second World War has been attributed to ecologic disruption. The same trends also led to the spread of different serotypes ofthe disease to different areas, and the emergence of dengue hemorrhagic fever, which was first reported in the Philippines in 1953. In the 1970s, it became a major cause of child mortality. Around the same time it emerged in the Pacific and the Americas. Dengue hemorrhagic fever and dengue shock syndrome were first noted in Middle and Southern America in 1981, as DENV-2 was contracted by...