Dengue fever (DF) is the most common mosquito-borne viral disease affecting humans worldwide, especially in tropical and subtropical regions. Dengue has been reported for more than 100 countries, with 2.5–3 billion people living in areas at potential risk of dengue transmission. It is estimated that 50–100 million patients of dengue occur annually of which 250,000 progress to DHF/DSS resulting in 24,000 deaths. This is the first study which documented the real prevalence, mortality and case fatality rate in dengue fever and compared the clinical features of classical dengue fever (CDF), dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS) in children and adults. The book will help the policy makers in developing the dengue control strategies as it revealed the change in seasonal trend of the disease occurrence and also the shift of affected people from children to adults. It will also help the physicians in the early diagnosis of dengue fever on the basis of symptoms and haematological parameters. The common people can also get benefit by knowing the temporal distribution, the characteristics symptoms, the major outcomes and the prevention strategies against the disease.