Dengue is spread by several species of mosquito of the Aedes type, principally A. aegypti. The virus has five different types; infection with one type usually gives lifelong immunity to that type, but only short-term immunity to the others.
When a body is starving for sugar, ketones take over and help breakdown the next best source of energy: stored fat. The body produces ketones during starvation or fasting and also during long bouts of physical training. When your muscles are sore after strenuous exercise - ketones cause the pain.
That depends. Ketosis is a normal metabolic process, something your body does to keep working. When it doesn't have enough carbohydrates from food for your cells to burn for energy, it burns fat instead. As part of this process, it makes ketones.