Hi, I would say pitterpat69's answers were all correct, with the exception that EBV can be transmitted anytime, by anyone who has been infected. As pitterpat69 said, when someone is asymptomatic, the chances of transmitting infection are much lower; however, the possibility is still there (maybe that is what she said, and I just read it wrong?). From everything I've learned though, EBV, CEBV (which is an ongoing EBV infection), and the person's reaction all depend on the person infected, which makes it very difficult to study.
I will attempt to answer each question to the best of my knowledge. I am not a doctor, but I have done extensive research on CEBV.
Are there different strains of EBV that cause Acute vs. Chronic active?
From what I understand, there are not different strains that cause acute vs chronic.
What makes EBV go from acute to chronic?
There are many factors that can go into whether or not someone develops chronic EBV. The medical community does not know all the reasons why someone develops EBV symptoms (either acute or chronic) and the next person does not. Studies have found that some people with chronic EBV can have compromised immune systems, but many with heathy immune systems can still develop chronic EBV. They have found that many with CEBV also have high levels of the stress hormone, cortisol, in their blood. Some have other viruses and infections that cause CEBV to flare up. Anything that depresses the immune system --even vaccines---can also cause a CEBV flare up. Unfortunately, there really aren't any clear-cut answers out there.
Is someone with chronic active EBV be contagious all the time?
Someone with CEBV is not contagious all the time. You are usually only contagious when you first get infected; however, the virus can appear in your saliva off and on for life. When this happens, it is called "shedding" and can happen when you are completely asymptomatic. Anyone who has been infected (and 90% of us have been infected by the age of 40) can periodically "shed" the virus. I suspect that my husband--who has never had mono or been sick with EBV---must have given it to me because I do not have close contact with anyone else's saliva. He NEVER got sick, but here I am with CEBV!
If someone with chronic active EBV infected someone else, does that mean the other person will be chronic active EBV forever? I am not sure here. What I read is that it depends on the individuals immune system.
No. See previous answers. The factors of the disease outcome appear dependent on the individual host--not the virus strain that was transferred.
You can have relationships because almost everyone has been exposed to this virus and only a tiny percentage of people ever develop CEBV. CEBV is not the result of the specific strain you might carry, it is a result of the factors I already listed and factors the medical community has not yet figured out. I