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Dengue fever results from infection by a flavivirus with four distinct serotypes (DEN-1, DEN-2, DEN-3, DEN-4). Aedis aegypti mosquitoes transmit dengue virus between humans. Dengue fever is endemic in much of Africa, Southeast Asia, and various tropical regions worldwide. Aedes albopictus mosquitoes are implicated to a lesser extent with dengue transmission in the Americas.
Dengue fever impacts 50 to 100 million people annually with several hundred thousand patients progressing to more severe cases of dengue hemorrhagic fever (DHF). Dengue hemorrhagic fever causes fatality in 5 percent of patients with this disease manifestation. -
Increased Vascular PermeabilityDengue virus causes an acute condition of increased vascular permeability and plasma leakage. Supporting the patient through this vascular crisis by proper hydration management leads to resolution. -
Regions of Activity and EndemicityDengue fever exhibits seasonal activity, with epidemics occurring during rainy seasons conducive to mosquito breeding. In endemic regions, dengue should be the presumed initial diagnosis when treating a patient with flu-like symptoms during the rainy season.
Dengue virus incubates three to fourteen days, after which dengue fever patients present with fever as high as 40 to 41 degrees C, myalgia, post-orbital pain, headache, appetite loss, nausea, vomiting, and petechial or maculopapular rash. Infants may present with undifferentiated febrile illness. Acute fever generally lasts three to seven days, often with a saddleback appearance where fever briefly remits and subsequently returns. Severe forms of dengue fever usually develop three to six days after disease onset. -
Dengue Fever PatientDifferential diagnosis includes other viral hemorrhagic fevers, malaria, measles, meningococcemia, leptospirosis, bacterial sepsis, typhoid fever, measles, rickettsial infections, rubella and influenza. Screenings include blood pressure, hydration status, tourniquet test, liver function, albumin level, pleural effusion index, CBC, and urology. Thirty percent of patients will present with hemorrhagic symptoms manifesting primarily as skin manifestations such a petechiae, echymoses, and purpura. Severe cases may also exhibit bleeding from the nose, gums, intestines, or an appearance of heavy menstruation. Urinalysis may indicate microhematuria.
Confirmation of infection with dengue virus by tissue culture or serology does not yield timely results for clinical decisions. Therefore, diagnosis relies on empirical clinical evidence.
Treatment for dengue fever and more severe manifestations of dengue hemorrhagic fever and dengue hemorrhagic shock is non-specific and supportive, consisting of pain relief and oral and/or IV administration of fluids. -
Administer IV FluidsWell-hydrated patients with no signs of increased vascular permeability may recover at home with instructions for follow-up if hemorrhagic symptoms appear. Patients exhibiting signs of hemorrhage or dehydration require clinical observation or hospitalization. Protect dengue fever patients' hospital beds with mosquito nets preventing further transmission.
It is important to avoid use of aspirin and nonsteroidal anti-inflammatory drugs in pain management, as this will exacerbate hemorrhagic complications. Acetaminophen is preferable.
Supervision of hydration forms the core of nursing management of dengue fever. Offer patients oral liquids regularly, give IV fluids with early signs of dehydration, and monitor urine output. Nurses also must monitor blood pressure and watch for signs of circulatory decompensation including a weak, rapid pulse, hypotension,and cold, clammy skin. World Health Organization dengue training materials provide the formula for calculating rehydration volume as twice that required for normal maintenance: 2 x (1500 mL + (20 x (weight in kg -- 20)) for patients over 40 kg.
Proper nursing management of dengue fever requires collection of multiple blood draws; serial hematocrits until one to two after fever resolution allow detection of hemoconcentration. Use an acute phase blood sample (days 0 to 5) taken at time of presentation for viral isolation in mosquito cell culture. Use convalescent samples for serotyping by ELISA. Collect tissue samples from the lymph nodes, lungs, liver, kidneys and spleen in fatal cases for immunohistochemistry studies.
Discharge requirements include two-day absence of fever, return of appetite, normal hematocrit and platelets above 50,000/mm^3. Patients recovering from shock should remain in observation at least three days after resolution of the circulatory crisis. Patients suffering respiratory distress from pleural effusion may need a longer hospitalization. -
Dengue Fever VirusNursing management of dengue fever also requires monitoring patients for signs of altered consciousness, confusion and other neurological implications. Watch for lethargy, seizures, nuchal rigidity, and paresis. Neurological involvement and intense, sustained abdominal pain with vomiting often signal development of more severe dengue hemorrhagic fever (DHF). Relief from fever and a sudden onset of hypothermia accompanied by restlessness and mental changes often precede onset of dengue hemorrhagic shock syndrome (DSS). - Previous infection with dengue fever does not confer cross-immunity to other dengue virus serotypes. Coinfection with multiple strains in endemic regions may contribute to increased virulence. A history of dengue fever or infection with multiple strains place patients at higher risk for dengue hemorrhagic fever (DHF).
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