<prompt> Dengue hemorrhagic fever is caused by: March 2010AlphavirusFlavivirusBunyavirusOrbivirus  <response>: Ans. B: Flavivirus Hemorrhagic dengueDengue shock syndromePhilippine hemorrhagic fever Thai hemorrhagic feverSingapore hemorrhagic fever is a severe, potentially deadly infection spread by ceain species of mosquitoes Aedes aegypti. It is caused by dengue virus type 1-4 belonging to genus flavivirus Early symptoms include: Decreased appetite - Fever - Headache - Joint aches - Malaise - Muscle aches - Vomiting Acute phase symptoms include: - Restlessness followed by: Ecchymosis Generalized rash Petechiae Worsening of earlier symptoms - Shock-like state Cold, clammy extremities Sweatiness diaphoretic Impoant tests: -- Liver enzymes -- Platelet count - Serologic studies demonstrate antibodies to Dengue viruses - Serum studies from samples taken during acute illness and convalescence increase in titer to Dengue antigen - Tourniquet test causes petechiae to form below the tourniquet - X-ray of the chest may demonstrate pleural effusion 