My Daughter Has Mono. Is the Whole Family at Risk?

While the infection itself is fairly common, symptomatic mononucleosis “is the less common presentation and occurs particularly in adolescents and young adults,” Razonable said. By midlife, over 90 percent of adults have been exposed to the virus, developed antibodies to it and gained immunity, he said, “so the majority of people actually will do well” if they are re-exposed to the virus, as long as they have a healthy immune system.

Symptoms of mononucleosis include a sore throat, enlarged tonsils, laryngitis, swollen lymph nodes in the neck or armpits, fever, head and body aches. Some patients become extremely fatigued, and some have a swollen liver or spleen.

A rash may develop, especially if patients were initially misdiagnosed with strep throat and started on a course of antibiotics. Since mono is a viral infection, antibiotics are not necessary and should be stopped.

The recommended treatment is to rest, drink plenty of fluids, and use over-the-counter medicine for fever and pain as necessary, Razonable said. Patients are also warned to avoid competitive sports because the spleen is at risk for rupture if it is enlarged.

To avoid becoming infected, people who are living with or caring for someone with mono should practice proper hygiene and wash their hands frequently. The virus is transmitted through saliva but is not airborne, so the main precautions are to avoid contact with saliva and to not share drinks, food, utensils or toothbrushes with the patient.

Patients usually recover within two to four weeks, but they may continue to shed the virus in their saliva, remaining infectious for months or even years, Razonable said. The virus can also occasionally become reactivated long after the illness has passed, and the person may become infectious again.