Disease Information for Dengue fever: Definition

  • An acute infectious, eruptive, febrile disease caused by four antigenically related but distinct serotypes of the DENGUE VIRUS; It is transmitted by the bite of infected Aedes mosquitoes, especially A aegypti; Classical dengue (dengue fever) is self-limiting and characterized by fever, myalgia, headache, and rash; DENGUE HEMORRHAGIC FEVER is a more virulent form of dengue virus infection and a separate clinical entity; Second infection worse with shock and hemorrhagic effects ; moderate hemorrhage and liver involvement; absent renal or encephalitis syndromes---------------(From Dorland, 28th ed)---------------------

    DENGUE FEVER Dengue fever is the most common arboviral infection and, in the form of dengue hemorrhagic fever (DHF), annually causes hundreds of thousands of life-threatening infections in the tropics, principally in children; Four dengue virus serotypes are predominantly transmitted by the Aedes aegypti mosquitoes, which are present in most tropical urban areas of the world; however, some other mosquito vectors are responsible for fairly substantial outbreaks; In the United States, these mosquitoes can be found during the summer in southeastern states, but autochthonous transmission of dengue virus occurs only in Texas; Epidemics arise in susceptible populations after the virus is introduced by viremic persons into areas with competent vectors; In areas where transmission is endemic, dengue is principally a disease of childhood; Infections occur in almost 100% of children before 8 years of age; In the absence of previous immunity, when new virus strains are introduced, or among travelers from nonendemic areas, infections occur in all age groups; Classic dengue is a grippe-like, often biphasic illness associated with fever, muscle and joint pains, chills, headache, and lumbar back pain accompanied by anorexia, nausea, and vomiting; Facial flushing is characteristic, and in fair-skinned persons, a centrifugally spreading morbilliform rash may be detected late in the illness; Illness is self-limited and sometimes is complicated by minor hemorrhagic phenomena, such as epistaxis and minor gum, gastrointestinal, and vaginal mucosal bleeding; A positive tourniquet test, and lowered platelet, total leukocyte, and absolute monocyte and neutrophil counts reflect marrow suppression; The above self-limited hemorrhagic phenomena should be differentiated from the hemorrhagic-shock syndrome, which is characterized by thrombocytopenia, generalized bleeding, and evidence of increased vascular permeability (eg, hemoconcentration, pleural or abdominal effusions, or hypoalbuminemia); Cross-immunity among the serotypes is limited, and sequential infection, particularly when dengue 2 virus causes the second infection, increases the risk for DHF/DSS; The interval of vascular instability may be as brief as 24 to 48 hours and reverses spontaneously; Sensitive clinical monitoring and supportive fluid, cardiovascular support, and the exclusion of aspirin reduce DHF mortality from 25% to less than 5%;

    ---------- [Rudolph"s Pediatrics 2002]-----------------