Infectious mononucleosis, also called “mono,” is a contagious disease. Epstein-Barr virus (EBV) is the most common cause of infectious mononucleosis, but other viruses can also cause this disease. It is common among teenagers and young adults, especially college students. At least one out of four teenagers and young adults who get infected with EBV will develop infectious mononucleosis.
Typical symptoms of infectious mononucleosis usually appear four to six weeks after you get infected with EBV. Symptoms may develop slowly and may not all occur at the same time.
- extreme fatigue
- sore throat
- head and body aches
- swollen lymph nodes in the neck and armpits
- swollen liver or spleen or both
nlarged spleen and a swollen liver are less common symptoms. For some people, their liver or spleen or both may remain enlarged even after their fatigue ends.
Most people get better in two to four weeks; however, some people may feel fatigued for several more weeks. Occasionally, the symptoms of infectious mononucleosis can last for six months or longer.
EBV is the most common cause of infectious mononucleosis, but other viruses can cause this disease. Typically, these viruses spread most commonly through bodily fluids, especially saliva. However, these viruses can also spread through blood and semen during sexual contact, blood transfusions, and organ transplantations.
Diagnosing Infectious Mononucleosis
Healthcare providers typically diagnose infectious mononucleosis based on symptoms.
Laboratory tests are not usually needed to diagnose infectious mononucleosis. However, specific laboratory tests may be needed to identify the cause of illness in people who do not have a typical case of infectious mononucleosis.
The blood work of patients who have infectious mononucleosis due to EBV infection may show—
- more white blood cells (lymphocytes) than normal
- unusual looking white blood cells (atypical lymphocytes)
- fewer than normal neutrophils or platelets
- abnormal liver function