Snapshot A 25-year-old male presents in the ED with a two day history of fever, severe frontal headache, myalgia, and joint pain. He developed a reddish, non-pruritic, non-blanching rash over his arms and back on the day of admission. He reports that he returned from a trip to Bali one week ago. There is no history of cough, sore throat, vomitting, and diarrhea. His temperature is 101.5°F (38.6°C), pulse is 119/min, respirations are 18/min, and blood pressure is 100/70 mmHg. Physical exam reveals an alert and oriented patient with a petechial rash on his back and upper arms. There is epigastric tenderness but no hepatosplenomegaly. Kernig sign is negative. Leukocyte count is 3600/mm3, Hct is 40%, and platelets are 95,000/mm3. Serum albumin is 2.8g/dL. IgM to dengue virus was detected by ELISA. Introduction Classification linear, enveloped(+) ssRNA flavivirus dengue virus Arthopod borne virus causing a painful and debilitating disease Epidemiology incidence infects ~390 million people a year as reported by the WHO causes approximately 25,000 deaths a year most US cases are secondary to those traveling abroad risk factors habitation in warm, wet areas of the world weak immune system and a second or subsequent infection put one at greater risk of dengue hemorrhagic fever female gender high BMI certain polymorphisms in specific genes location SE Asia Caribbean tropics Transmission via female Aedes aegypti mosquitos not transmitted from person to person once in a human, the virus can be transmitted by blood products organ transplants vertical transmission has been reported Presentation Symptoms virus incubation period of approximately 4-7 days mild dengue fever sudden, high fever severe headaches periorbital pain nausea vomiting skin rash myalgias dengue hemorrhagic fever (often a result of a strong initial immune response, and secondary antigen exposure) high fever damage to lymph and blood vessels bleeding from nose/gums hepatomegaly dengue shock syndrome massive bleeding shock death Physical exam pleural effusions ascites low pulse pressure Evaluation Labs low leukocyte count thrombocytopenia metabolic acidosis moderately elevated AST and ALT hemoconcentration hypoalbuminemia Diagnosis PCR useful in the acute phase of illness dengue-specific antibody detection help to confirm diagnosis in later stages of infection Differential Differential diagnosis Lassa fever Ebola fever Marburg fever Chikungunya Treatment Supportive care no specific treatments have been developed yet pain relievers acetaminophen avoid aspirin - can worsen the bleeding IVF hospitalization Prognosis, Prevention, and Complications Prognosis 80% of cases are asymptomatic or mild illness 5% of cases result in severe illness only a small percentage will be life threatening Prevention no vaccine available vector control mosquito repellant Complications dengue shock syndrome