Some also experience headaches, decreased appetite, abdominal pains, and rash. Most people are somewhere in between and may need to take time off from work or classes. Symptoms develop about four to six weeks from the time of exposure. During this time you feel well. This test usually turns positive shortly after the onset of symptoms, but in some cases the test will remain negative for one week or longer despite illness.
Some people never develop a positive test.
In such cases your clinician may order more specific blood tests to establish the diagnosis. Other tests called blood counts and liver tests may be ordered to help rule out some of the complications associated with mono. The illness may last seven to ten days, but varies widely from person to person. The vast majority of people recover completely. The EB virus begins to be shed in th throat with the onset of symptoms and continues during the illness.