Feeling ill from a virus most often but not always coincides with that virus reproducing. It becomes contagious at that point because the newly increased viral load is “shedding” in mucous, saliva and/or sweat, meaning the virus is present in those bodily fluids and therefore can infect other people. Before that point, the typical aches and fever are not present. That’s the immune response once the immune system recognizes that the virus is an infection to be fought off. Aches and pains are due to new white blood cells, etc. being produced, as well as an inflammation response. The immune reaction causes the symptoms rather than the virus itself.
Yup. But there are viruses that are contagious before symptoms appear though. Herpes (cold sores) is one example. This strain of Ebola MIGHT be another in some cases according to some studies. (No link - too tired and frustrated - but you can easily find them if you search.).
Again, MIGHT.
Thank you for the explanation.
Now is the virus not present in body fluids until the time that aches and pains present themselves? Or is it present but just not in numbers sufficient to pose any threat to others?
It just seems curious to me that someone can have the virus in their system but have no possibility of passing it along. Maybe that is the case, or maybe it is a vanishingly small possibility until there is enough of a virus load to provoke an immune response. I certainly don’t know enough about how viruses behave to have an informed opinion.