Ans. Dengue fever is an infectious disease spread by Aedes mosquitoes and caused by dengue virus. Its virus has four different sub-types (serotypes), each causing a different type. 6f fever. Immunity developed against one type js ineffective against other three types, and till today no vaccine is available.
The incubation period usually is four to seven days before the symptoms of the disease appear in the infected person. The . principal symptoms of the disease in mild dengue type of fever are:
1. High fever usually above 102-104°F with low heart beat and blood pressure, The fever starts with chills, nausea or rash on skin.
2. Severe headache and pain behind the eyes.
3. Pain in muscles and joints because of which it is also called "Break Bone ' Fever".
4. Gradually the white blood cells and platelets count decrease. Patient feels '. weakness and fatigue. '