Dengue hemorrhagic fever is caused by: March 2010

Ans. B: Flavivirus Hemorrhagic dengue/Dengue shock syndrome/Philippine hemorrhagic fever/ Thai hemorrhagic fever/Singapore 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)