All are true regarding dengue fever except:

Ans: b (Subclinical cases are not seen)Ref: Park 19 ed, p. 206,207Dengue virus is an arbovirus, vector being Aedes aegypti and Aedes albopictus with 4 serotypes:Epidemiology of dengue fever:About 1.3 billion people are living in dengue endemic areas. By 1997, most of the countries of SouthEast Asian Region have experienced large outbreaks of the disease. Over the past 10-15 years, next to diarrhoeal disease and acute respiratory disease, dengue has become a leading cause of hospitalization and deaths among children in SEAR.Countries in SEAR have been divided into 4 categories based on prevalence of the disease.Cat A: Major health problemCat B: Emerging disease with cyclical epidemics (India falls this category)Cat C: Endemicity uncertainCat D: Non endemicCriteria for clinical diagnosis of DHF:1) High grade continous fever lasting for 2- 7 days2) Hemorrhagic manifestations including atleast a positive tourniquet test.3) HepatomegalyLab diagnosis1) Thrombocytopenia (100,000/Mm3 or less)2) Hemoconcentration: Hematocrit increased by 20%Dengue shock syndrome(DSS)1) All the above criteria plus shock manifested by rapid and weak pulse and narrowing of pulse pressure or hypotension with cold clammy skinManagement::Symptomatic and supportive