dengue

/deng"gay, -gee/, n. Pathol.

an infectious, eruptive fever of warm climates, usually epidemic, characterized esp. by severe pains in the joints and muscles. Also called dengue fever.

[1820-30, Amer.; < AmerSp]

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or breakbone fever or dandy fever

Infectious, disabling mosquito-borne fever.

Other symptoms include extreme joint pain and stiffness, intense pain behind the eyes, a return of fever after brief pause, and a characteristic rash. Dengue is caused by a virus carried by mosquitoes of the genus Aedes, usually A. aegypti, which also carries yellow fever. There are four strains of virus; infection with one type does not confer immunity to the remaining three. Treatment focuses on relieving symptoms. Patients should be isolated during the first three days, when mosquitoes can pick up the disease from them. Prevention relies on mosquito control.

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▪ disease

Introduction

also called  breakbone fever, or dandy fever,  

 acute, infectious, mosquito-borne (mosquito) fever that is temporarily incapacitating but is rarely fatal. Besides fever, the disease is characterized by an extreme pain in and stiffness of the joints (joint) (hence the name “breakbone fever”). Complication of dengue fever can give rise to a more severe form, called dengue hemorrhagic fever (DHF), which is characterized by hemorrhaging blood vessels (blood vessel) and thus bleeding from the nose, mouth, and internal tissues. Untreated DHF may result in blood vessel collapse, causing a usually fatal condition known as dengue shock syndrome. Dengue is caused by one of four viral serotypes (closely related viruses (virus)), designated DEN-1, DEN-2, DEN-3, and DEN-4. These serotypes are members of the Flavivirus genus, which also contains the viruses that cause yellow fever, and can occur in any country where the carrier mosquitoes breed.

Viral transmission

      The carrier incriminated throughout most endemic areas is the yellow-fever mosquito, Aedes aegypti. The Asian tiger mosquito, A. albopictus, is another prominent carrier of the virus. A mosquito becomes infected only if it bites an infected individual (humans and perhaps also certain species of monkey) during the first three days of the victim's illness. It then requires 8 to 11 days to incubate the virus before the disease can be transmitted to another individual. Thereafter, the mosquito remains infected for life. The virus is injected into the skin of the victim in minute droplets of saliva. The spread of dengue is especially unpredictable because there are four serotypes of the virus. Infection with one type—though it confers lifetime immunity from reinfection with that type of dengue—does not prevent an individual from being infected by the other three types.

Diagnosis and treatment

      Diagnosis is made on clinical findings, namely, sudden onset, moderately high fever, excruciating joint pains, intense pain behind the eyes, a second rise in temperature after a brief remission, and particularly the type of rash and decided reduction in neutrophilic white blood cells (leukocyte). There is no specific therapy; therefore attention is focused on relieving the symptoms. In DHF prompt medical attention on maintaining circulating fluid volume can improve chances for survival.

      Temporary preventive measures must be taken to segregate suspected as well as diagnosed cases during their first three days of illness and, by screens and repellents, to keep mosquitoes from biting more people. Fundamental in the control of the disease is the destruction of mosquitoes and their breeding places.

Dengue through history

      The earliest account of a denguelike disease comes from the Jin dynasty (AD 265–420) in China. There is also evidence that epidemics (epidemic) of illnesses resembling dengue occurred in the 17th century. However, three epidemics that took place in the late 18th century mark the arrival of the disease that is today recognized as dengue fever. Two of these outbreaks involved an illness decidedly similar in symptoms and progression to dengue, and both occurred in 1779—one in Cairo and the other in Batavia (now Jakarta) in the Dutch East Indies (now Indonesia), which was reported by Dutch physician David Bylon. The third epidemic happened in 1780 in Philadelphia, Pa. American statesman and physician Benjamin Rush (Rush, Benjamin), who treated afflicted patients during the Philadelphia epidemic, provided the first clinical description of dengue in his Account of the Bilious, Remitting Fever, which was published in 1789. Because all three 18th-century epidemics involved very similar diseases and occurred in port cities, it is believed that dengue virus was spread from one continent to another via ships. Thus, the spread of dengue depended on overseas survival of mosquito vectors, as well as on arrival in areas with both the necessary environmental conditions to support vector survival and a susceptible population into which the virus could be introduced. This pattern of transport probably also facilitated the emergence of new viral serotypes.

      In the early 1900s Australian naturalist Thomas Lane Bancroft identified Aedes aegypti as a carrier of dengue fever and deduced that dengue was caused by an organism other than a bacterium (bacteria) or parasite. During World War II, dengue emerged in Southeast Asia and rapidly spread to other parts of the world, inciting a pandemic. Around this time the causative flavivirus was isolated and cultured independently by Japanese physicians Susumu Hotta and Ren Kimura and by American microbiologist Albert Bruce Sabin (Sabin, Albert Bruce). In the 1950s hemorrhagic dengue appeared in Southeast Asia, where it became a common cause of death among children in the 1970s. The serotypes continued to spread on a pandemic level, eventually reaching areas of South and Central America, Cuba, and Puerto Rico, where in 1977 an epidemic lasting from July to December affected some 355,000 people. In the following decades the increasing incidence of dengue, particularly DHF, persisted. In 2008 the World Health Organization reported that approximately 2.5 billion people worldwide were at risk of dengue and that the disease was endemic in more than 100 countries.

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