Dengue and Dengue Hemorrhagic Fever.By Gubler, D.J.
Gubler, D.J. 1998. Dengue and Dengue Hemorrhagic Fever. Clinical Microbiology Reviews 11(3): 480–496.
Dengue fever, a very old disease, has reemerged in the past 20 years with an expanded geographic distribution of both the viruses and the mosquito vectors, increased epidemic activity, the development of hyperendemicity (the cocirculation of multiple serotypes), and the emergence of dengue hemorrhagic fever in new geographic regions. In 1998 this mosquito-borne disease is the most important tropical infectious disease after malaria, with an estimated 100 million cases of dengue fever, 500,000 cases of dengue hemorrhagic fever, and 25,000 deaths annually. The reasons for this resurgence and emergence of dengue hemorrhagic fever in the waning years of the 20th century are complex and not fully understood, but demographic, societal, and public health infrastructure changes in the past 30 years have contributed greatly.
Although first reports of major epidemics of an illness thought to possibly be dengue occurred on three continents (Asia, Africa, and North America) in 1779 and 1780 (73, 75, 109, 128), reports of illnesses clinically compatible with dengue fever occurred even earlier. The earliest record found to date is in a Chinese encyclopedia of disease symptoms and remedies, first published during the Chin Dynasty (265 to 420 A.D.) and formally edited in 610 A.D. (Tang Dynasty) and again in 992 A.D. (Northern Sung Dynasty) (108). The disease was called water poison by the Chinese and was thought to be somehow connected with flying insects associated with water.
Dengue in the Continental United States
Each year, dengue cases imported to the Continental United States are documented by the Centers for Disease Control and Prevention (CDC) (40, 119). These cases represent introductions of all four virus serotypes from all tropical regions of the world.
The adult mosquitoes prefer to rest indoors, are unobtrusive, and prefer to feed on humans during daylight hours. There are two peaks of biting activity, early morning for 2 to 3 h after daybreak and in the afternoon for several hours before dark. However, these mosquitoes will feed all day indoors and on overcast days. The female mosquitoes are very nervous feeders, disrupting the feeding process at the slightest movement, only to return to the same or a different person to continue feeding moments later. Because of this behavior, A. aegypti
females will often feed on several persons during a single blood meal and, if infective, may transmit dengue virus to multiple persons in a short time, even if they only probe without taking blood (46, 112, 114, 135). It is not uncommon to see several members of the same household become ill with dengue fever within a 24- to 36-h time frame, suggesting that all of them were infected by a single infective mosquito (43). It is this behavior that makes A. aegypti
such an efficient epidemic vector. Inhabitants of dwellings in the tropics are rarely aware of the presence of this mosquito, making its control difficult.