Q. Last year, my wife was told by her doctor that she tested positive for Epstein Barr virus infection. I asked her doctor if he could give us any information on this virus, but he said there wasn't much information available, just that it was very rare. I went to our local library, but found no information. Could you tell us more about this virus?

Are there any organizations that provide information about this problem?

A. I can tell you more about the Epstein Barr virus, but you didn't give me much information to go on. Let me guess that your wife's problem was being tired all the time and that her doctor blamed EBV infection for it. If so, you may need to rethink what's really going on.

Named for the two physicians who discovered it, Epstein Barr virus is not rare at all. In fact, most people have been exposed to it by the time they reach adulthood. EBV is best known for causing infectious mononucleosis, also known as "mono" or the "kissing disease." But many people get infected with this virus without developing any symptoms.

Mono is an illness that resembles strep throat. The main symptoms are fever, sore throat and swollen glands in the neck. Mono is also known for making you feel tired and run down. It's called the kissing disease because kissing is the most common way the infection gets passed from person to person.

A couple of years ago, EBV got a lot of publicity as the supposed cause of chronic fatigue. Because this virus lies dormant in your body after you're infected with it and because fatigue is a common symptom of mono, researchers speculated that EBV might explain cases of chronic fatigue where the cause wasn't readily apparent. New research now proves this notion wrong.

The tricky part about linking EBV with chronic fatigue -- or any illness for that matter -- is this: Once people become infected with EBV, they form antibodies against it. Antibodies are molecules your white blood cells make to fight foreign substances, such as bacteria and viruses. In most cases, the antibodies against EBV stay in your bloodstream for the rest of your life. So, if you see your doctor because you're tired all the time and he tests your blood for EBV, it's likely to come out positive.

At first, researchers thought they could use special tests to distinguish between people who happened to have antibodies to EBV as a result of an old infection from people with fatigue caused by EBV. Now, it appears that this just isn't the case.

As it turns out, the vast majority of people with antibodies to EBV don't have chronic fatigue, and many people with chronic fatigue don't have antibodies to EBV. In fact, some researchers tried treating people who had chronic fatigue with the drug acyclovir, a medicine that in theory should fight EBV infection. The treatment didn't help. In spite of some exciting leads, the link between EBV and chronic fatigue just hasn't panned out.

In an upcoming column, I'll discuss the problem of chronic fatigue: what causes it, how to diagnose it and how to treat it. I'll also mention some support groups and sources for more information. More on Organ Donation

As a follow-up to my recent discussion about donating organs or tissues at the time of death, I'd like to address some of the most frequent concerns about being a donor.

There is no cost involved to the family, nor is any payment made for the donation.

Donation doesn't interfere with funeral arrangements, including being able to have an open casket.

Organ donation is compatible with most religions.

The donor is legally dead before any donation takes place.

You should make your wishes known to your family. Though not legally required, most organ donation occurs with the knowledge and consent of your next of kin.

It is not necessary to mention your desire to be an organ donor in your will. In fact, by the time your will is processed, the opportunity for organ donation would long be gone.

Uniform donor cards can be obtained from the American Council on Transplantation, 700 N. Fairfax St., Suite 505, Alexandria, Va., 22314; the Living Bank, P.O. Box 6725, Houston, Tex. 77265 (1-800-528-2971), or the United Network for Organ Sharing, P.O. Box 13770, 1100 Boulders Parkway, Suite 500, Richmond, Va. 23225 (1-800-24-DONOR).

In some states, such as Maryland, you also can designate on your driver's license that you are a registered organ donor.

No matter how old you are or what illnesses you may have, chances are you're still eligible to be an organ or tissue donor.

Jay Siwek, a family physician from Georgetown University, practices at the Fort Lincoln Family Medicine Center and Providence Hospital in Northeast Washington.

Consultation is a health education column and is not a substitute for medical advice from your physician.

Send questions to Consultation, Health Section, The Washington Post, 1150 15th St. NW, Washington, D.C. 20071. Questions cannot be answered individually.