Analysis of data obtained from discrete variables requires the use of specific statistical tests which are different from those used to assess continuous variables (such as cardiac output, blood pressure, or PaO 2) which can assume an infinite range of values.
Primary symptoms of dengue appear three to 15 days after the mosquito bite and include the following: 1  high fever and severe headache, 2  with severe pain behind the eyes that is apparent when trying to move the eyes.
Dengue hemorrhagic fever is characterized by a fever that lasts from 2 to 7 days, with general signs and symptoms consistent with dengue fever. When the fever declines, symptoms including persistent vomiting, severe abdominal pain, and difficulty breathing, may develop.