**4.1.9 Clinical definition**

Dengue case was defined on the bases of presence of IgM, IgG, or fourfold or greater rise in hemagglutination inhibiting (HI) antibody titer against dengue virus, and presence of dengue virus specific nucleic acids in RT-PCR. Clinical severity was defined as presence of hemorrhagic manifestation and DHF related symptoms such as thrombocytopenia, skin rash, gum bleeding, gastrointestinal bleeding, hemorrhagic sclera, epistaxis, edema and ascitis. Where as other studies simply defined as presence of DF, DHF grade I, II and III and DSS as per WHO criteria.
