The virus that is responsible for the disease known as infectious mononucleosis, or mono, is called the Epstein-Barr virus. Most commonly, the Epstein-Barr virus, or EBV, infects a person without his being aware of it. According to the medical reference UpToDate, about 90 to 95 percent of adults test positive for antibodies to EBV, indicating that they've been infected and successfully fought off the infection. EBV, however, can cause a variety of infections, ranging from simple mononucleosis to meningitis.
Infectious Mononucleosis
UpToDate notes that infectious mononucleosis is one of the most well-known diseases caused by EBV. It is sometimes called the "kissing disease" because it is spread by contact with an infected person's saliva. Symptoms at the start of infectious mononucleosis include a general feeling of discomfort called malaise, as well as a low-grade fever and headache. As the infection progresses, the fever gets higher, the throat and tonsils become inflamed and the lymph nodes of the neck will be swollen. Most of these symptoms will disappear within a week or two. One of the symptoms of mononucleosis--extreme, potentially debilitating tiredness--may last for months after the other symptoms disappear.
Infections of the Nervous System
While most people are infected with EBV without ever being aware of it, some people have manifestations of the infection that are more serious. For example, meningoencephalitis is a potentially life-threatening infection of the layers of tissue around the brain, called the meninges, and the brain itself. Symptoms of meningoencephalitis may include a stiff neck--this is an indication that the meninges are infected--as well as a change in cognition and level of consciousness, ranging from confusion to a complete lack of consciousness. The Epstein-Barr virus can also affect other parts of the nervous system. If the optic nerve--the nerve directly behind the eye that carries light and vision information to the brain--is affected, it is called optic neuritis and can cause sudden changes in vision, such as blurring, or pain, which may be experienced as dull ache or sharp, stabbing.
EBV Infections of Other Organs
Infection with Epstein-Barr virus is unfortunately not limited to a bout of infectious mono or even the more serious potential infections of the nervous system. In fact, EBV may cause infection in nearly any organ in the body. If it infects the lungs, the patient will develop pneumonia, with symptoms such as a cough, fever and shortness of breath. If the heart is infected, the condition is called myocarditis, and may result in the patient experiencing heart failure, difficulty exercising and fatigue. If a patient notices these types of symptoms, he should contact his physician, as further examination and evaluation may be needed.
References
- MedlinePlus: Infectious Mononucleosis
- "UpToDate"; Clinical manifestations and treatment of Epstein-Barr virus infection; John Sullivan; August 2009
- National MS Society: Optic Neuritis
