Dengue and Dengue Hemorrhagic Fever

Abstract

SUMMARY 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. This paper reviews the changing epidemiology of dengue and dengue hemorrhagic fever by geographic region, the natural history and transmission cycles, clinical diagnosis of both dengue fever and dengue hemorrhagic fever, serologic and virologic laboratory diagnoses, pathogenesis, surveillance, prevention, and control. A major challenge for public health officials in all tropical areas of the world is to devleop and implement sustainable prevention and control programs that will reverse the trend of emergent dengue hemorrhagic fever.

Climate change and threat of vector-borne diseases in India: are we prepared?

“…In addition to temperature, rainfall and RH are the main limiting factors for ensuing transmission (Ansari and Razdan 1998;Sharma et al 2005). Main reasons of dengue epidemics have been found to be urbanisation, lack of surveillance and vector control, introduction of new serotypes in new areas and population movement (Gubler 1997(Gubler , 1998Gupta et al 2005Gupta et al , 2006. Urbanisation, piped water supply and scarcity of water leading to water storage practices are also the important responsible factors for exacerbation of dengue (Sharma 1998).…”

Dengue illness: clinical features and pathogenesis

“…The transmission cycle of dengue viruses involves the Aedes mosquito and lower primates in the rain forests of Asia and Africa. 1 These viruses do not move out of the forest into urban areas, but an epidemic transmission cycle in rural villages and islands may be possible. A number of Aedes mosquitoes, such as Aedes aegypti and A. albopictus, may act as a vector in these situations.…”

“…1 Infection with one serotype confers immunity to the infected serotype for a long period, but not to other serotypes. Humans may therefore be infected with the dengue virus up to four times.…”

“…After an infected mosquito has bitten a human, the virus replicates in the regional lymph nodes and is then disseminated into the blood circulation and other organs. 1,4 The incubation period is typically 4-7 days. DF is characterized by the sudden onset of fever and other nonspecifi c symptoms, such as headaches.…”

Field evaluation of the efficacy of proprietary repellent formulations with IR3535® and Picaridin against Aedes aegypti

“…Due to its biology and its geographic range, A. aegypti is the most important vector of both yellow fever and dengue fever/dengue haemorrhagic fever. Although a vaccine exists against yellow fever, the disease is still considered a threat in much of Africa and Latin America (WHO 2006;Diallo et al 2003;Gubler 1998). Dengue threatens an approximated 2.5 billion people worldwide and no specific medication or vaccination is available (WHO 2002;CDC 2005).…”