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.
5. Early Ebola symptoms are also symptoms of other viral infections. Early Ebola symptoms include fever, headache, body aches, cough, stomach pain, vomiting, and diarrhea. Because these could be symptoms of other diseases, it's difficult to diagnose Ebola early on.