Friday, January 26, 2007
-Initiate supportive therapy
-Intravenous (IV) crystalloids, as needed to keep systolic blood pressure above 90 mm Hg
Emergency Department Care
-IV access, O2, and monitoring are helpful.
-IV crystalloids may be necessary for hypotension; central line may be needed.
-Correct electrolyte abnormalities and acidemia.
-Implement therapy for DIC if indicated.
-Corticosteroids are not helpful.No antiviral therapy is available
-Abrupt onset, rising to 39.5-41.4°C
-Accompanied by frontal or retro-orbital headache
-Lasts 1-7 days, then defervesces for 1-2 days
-Biphasic, recurring with second rash but not as high
-Initial rash transient, generalized, macular, and blanching; occurs in first 1-2 days of fever
-Second rash occurring within 1-2 days of defervescence, lasting 1-5 days
-Second rash morbilliform, maculopapular, sparing palms and soles
-Absent in DHF(dengue haemorrhagic fever) / DSS (dengue shock syndrome)
-After onset of fever
-Increases in severity
-Not associated with fractures
-May last several weeks
-Most common in legs, joints, and lumbar spine
-Nausea and vomiting
-Abdominal pain (severe in DHF/DSS)
From Physical Examination:
-Signs of intravascular volume depletion
-Hypotension with narrowed pulse pressure
-Delayed capillary refill
-Positive tourniquet test
-Petechiae, purpura, epistaxis, gum bleeding, GI bleeding, menorrhagia
Dengue viral infections frequently are not apparent. Classic dengue primarily occurs in nonimmune, nonindigenous adults and children. Symptoms begin after a 5- to 10-day incubation period. DHF/DSS usually occurs during a second dengue infection in persons with preexisting actively or passively (maternally) acquired immunity to a heterologous dengue virus serotype. Illness begins abruptly with a minor stage of 2-4 days' duration followed by rapid deterioration. Increased vascular permeability, bleeding, and possible DIC may be mediated by circulating dengue antigen-antibody complexes, activation of complement, and release of vasoactive amines. In the process of immune elimination of infected cells, proteases and lymphokines may be released and activate complement coagulation cascades and vascular permeability.
The grade of fever
Low grade fever: 37.3~38 C
Moderate fever: 38~39 C
High fever: 39.1~41 C
Hyperthermia fever: more than 41 C
-Fever to 106°F (41.1°C), which a healthy adult body can tolerate for several hours.
-The brain's thermostat will stop the fever from climbing above 106° (41.1C)
-Cells do not die off until 110°F (43.3°C) is reached.
The first reported epidemics of DF occurred in 1779-1780 in Asia, Africa, and North America. The near simultaneous occurrence of outbreaks on three continents indicates that these viruses and their mosquito vector have had a worldwide distribution in the tropics for more than 200 years. During most of this time, DF was considered a mild, nonfatal disease of visitors to the tropics. Generally, there were long intervals (10-40 years) between major epidemics, mainly because the introduction of a new serotype in a susceptible population occurred only if viruses and their mosquito vector could survive the slow transport between population centers by sailing vessels.
A pandemic of dengue began in Southeast Asia after World War II and has spread around the globe since then. Epidemics caused by multiple serotypes (hyperendemicity) are more frequent, the geographic distribution of dengue viruses and their mosquito vectors has expanded, and DHF has emerged in the Pacific region and the Americas. In Southeast Asia, epidemic DHF first appeared in the 1950s, but by 1975 it had become a frequent cause of hospitalization and death among children in many countries in that region.
Thursday, January 25, 2007
Dengue is a homonym for the African ki denga pepo, which appeared in English literature during an 1827-28 Caribbean outbreak. The first definite clinical report of dengue is attributed to Benjamin Rush in 1789, but the viral etiology and its mode of transmission via mosquitos were not established until the early 20th century.