Ask Emily

30 11 2011

Can you have mono more than once?

Mononucleosis, known as the “kissing disease” in my youth, is a viral disease that has engendered many a myth. The idea that you can have the nonspecific group of symptoms we call “mono” only once is just one of them.

Unless specified by the virus that causes it, the term mononucleosis is a general name for a suite of symptoms of viral illness. These symptoms include swollen glands, fever, sore throat, and fatigue. The spleen will swell along with the lymph nodes, and even after the acute fever and sore throat depart, the fatigue and a feeling of unwellness may last several weeks.

The virus that is most associated with mono is the Epstein-Barr virus, or EBV. EBV often infects people who show no symptoms, but in some cases, the infection is more serious.

In rare cases, the virus can remain active over the long-term without showing symptoms, and may be associated with several autoimmune diseases. Another possible outcome of long-term EBV activity can even more rarely be certain kinds of lymphoma.

This virus is so common that in the United States, up to 95% of adults in their thirties and forties may have been infected at some point in their lives. In younger folk—teens and children—exposure results in symptoms in up to half of cases.

But EBV is not the only agent that can produce the illness we generally call mononucleosis. Other viruses, including cytomegalovirus or adenovirus, can cause mono, as can an infection with the protozoan that causes toxoplasmosis.

The symptoms can be very similar, and the only way to be sure that the cause was EBV is to undergo tests to confirm it.

Usually, if you’ve had a specific virus once, your body develops immunity to it, and you’ll avoid getting sick the next time you’re exposed. But given the tendency of EBV to sometimes linger in the body, some people may experience its reactivation, which may or may not cause symptoms. During reactivation, symptoms or not, a person can pass EBV to someone else, primarily through exposure to saliva or other very close contact.

Also, if you had what you thought was mononucleosis but it was caused by a different virus, such as cytomegalovirus, then you can obviously have “mono” again if you pick up EBV and experience symptoms. Thus, the final answer to the question is, Yes, you can have mononucleosis more than once.

By Emily Willingham

Image courtesy of mugley