General considerations

00000000Dengue fever (DF) is an acute febrile viral disease frequently presenting with headaches, bone or joint and muscular pains, rash and leukopenia as symptoms. Dengue haemorrhagic fever (DHF) is characterized by four major clinical manifestations: high fever, haemorrhagic phenomena, often with hepatomegaly and, in severe cases, signs of circulatory failure. Such patients may develop hypovolemic shock resulting from plasma leakage. This is called dengue shock syndrome (DSS) and can be fatal.

00000000 Dengue or dengue-like epidemics were reported throughout the nineteenth and early twentieth centuries in the Americas, southern Europe, North Africa, the eastern Mediterranean, Asia and Australia, and on various islands in the Indian Ocean, the south and central Pacific and the Caribbean. As discussed below, DF and DHF have steadily increased in both incidence and distribution over the past 40 years, and in 1996, 2500 - 3000 million people live in areas potentially at risk for dengue virus transmission. Annex 1 lists countries or territories by WHO Region in which DF or DHF is known to have occurred between 1975 and 1996. Figure 1.1 is a map illustrating the same information. Reported cases of DF and DHF for the period 1956 - 1995 are shown in Table 1.1.

00000000 Dengue in the South-East Asia and Western Pacific Regions of WHO

00000000The disease now known as DHF was first recognized in the Philippines in 1953. The syndrome was etiologically related to dengue viruses when serotypes 2, 3 and 4 were isolated from patients in the Philippines in 1956; 2 years later dengue viruses of multiple types were isolated from patients during an epidemic in Bangkok, Thailand. During the next three decades, DHF/DSS was recognized in Cambodia, China, India, Indonesia, the Lao People's Democratic Republic, Malaysia, Maldives, Myanmar, Singapore, Sri Lanka, Viet Nam, and several Pacific Island groups.
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1 In this book "dengue" refers to the entire spectrum of dengue viral disease; abbreviations (i.e. DF, DHF, DSS) are used to refer to specific gradations of dengue.