Clinical Virology Programs

As thousands of students head back to class this fall, many will find their studies interrupted by the arrival of an unwelcome illness–infectious mononucleosis, or mono.

Sometimes referred to as the “kissing disease,” mono is caused by a virus, usually the Epstein-Barr virus, which is spread through contact with saliva or mucus. Once a person is exposed to the Epstein-Barr virus, he or she may spread it to others, even if the person is symptom-free. This makes it of particular concern on college campuses, where many students are housed in close quarters.

Mono is commonly spread through direct contact with the saliva of an infected person, usually through kissing. While common sense dictates not sharing eating utensils, or drinking out of the same glass, these are not the usual modes of transmission.

Viral Loads Show Why Mono Is the Kissing Disease

As the result of a prospective study of University of Minnesota students who presented to the Boynton Health Service within a week of developing mono symptoms, we know how quantities of EBV, or “viral loads,” change during mono (J Infect Dis. 2005;192:1505-12). Symptoms in students with mono due to primary EBV infection lasted an average of three weeks. As shown in Figure 1, EBV left the bloodstream rapidly but persisted in large quantities in the saliva and oral cells for months. This observation confirmed the aptness of mono’s sobriquet, “the kissing disease,” because plenty of virus was detected in the oral secretions long after symptoms abated and students had presumably resumed their usual social activities.

We are using a “homebrew” molecular assay (real-time PCR with TaqMan chemistry targeted at a portion of the EBV EBNA1 gene) to measure the amount of EBV in body fluids. During the acute illness, students with serologically confirmed primary EBV infection had a median of 10,000 copies of EBV/mL of whole blood and a median of 32,000 copies of EBV/mL of saliva. In contrast, students whose mono-like symptoms were not due to primary EBV infection had a median of <1,000 EBV copies/mL in both whole blood and saliva. Data from the mono subjects with primary EBV infections who were not given antiviral therapy provided the necessary background information for designing studies to find the answer to the question below.

The two most typical symptoms of the disease are a very sore throat and extreme fatigue. People with mono also can have a fever and swollen glands. These symptoms can last from two to three weeks; however, some people still feel rundown several months after being diagnosed. In rare cases, a person’s spleen may become enlarged. While mono is a relatively minor disease, it causes sufferers to miss countless hours of time at work and school.

The disease occurs most commonly in those ages 15-25, or high school and college students, who often lose valuable time with their studies after being infected.

Currently, the standard treatment for mono involves getting plenty of rest and taking painkillers such as acetaminophen or ibuprofen to relieve fever, sore throat pain, and headaches. In extreme cases, doctors may prescribe anti-inflammatory drugs and steroids.