General Health Topic Mononucleosis

What is Mono and what causes it?
Mononucleosis is an illness caused by a virus. The Epstein-Barr Virus (EBV) is the usual cause of infectious mono. However, infections with other viruses can cause a mono-like illness.

Who gets Mono?
Mono is an illness mainly of adolescents and young adults. Usually the person has been exposed to the virus 30 to 50 days before developing symptoms.

What are the symptoms?
Typical symptoms include a sore throat, fatigue, swollen glands, fever and headache. Sometimes a skin rash will occur.

How is Mono diagnosed?
The symptoms and physical exam help in diagnosing mono. A blood-test is usually done to diagnose and confirm mono. However, it can take 5 to 7 days before the blood test for mono is accurate. Because the symptoms are similar to other illnesses, a definite diagnosis is not always possible early in the illness. If a person initially tests negative for mono and the symptoms persist, a follow-up visit with your health care provider may be necessary and the test may need to be repeated. A mono blood test will not predict the severity of the illness nor will it predict how long the symptoms will last.

Even if a person has most of the symptoms listed above, the mono test may be negative and the person may not have mono because of the number of other viruses that can cause “mono-like” illness.

How is mono passed?

Mono is not highly contagious and many college students are immune to mono without knowing it. Mono is passed by close contact, not by casual contact with roommates or friends. Mono is spread through saliva so intimate contact (kissing, sharing drinking glasses, etc.) is the usual method of spreading mono. Rarely will a person know from whom or how they became infected. The virus remains in the saliva for 30 to 45 days so individuals need to avoid kissing and close contact for that period of time.

The virus that causes mono can remain in the saliva of individuals who have had mono for long periods of time. The virus can be in the saliva (and capable of being passed to another person) on and off for a lifetime.

How is mono treated?

Unfortunately there is no medicine to "cure" mono. Antibiotics do not treat viral infections such as mono. However, your own immune system will fight off the infection and help you recover if you take proper care of yourself when you are sick.

The treatment for mono is to relieve the symptoms. Get adequate rest and drink lots of fluids. You may take ibuprofen or acetaminophen to help with the fever, sore throat, and other aches and discomforts of mono. For the sore throat, throat lozenges, topical sprays such as Chloraseptic, gargles with warm water, hard candy, and Popsicles may help.

Mono can cause some mild changes in the liver’s ability to function. Although these will return to normal as you recover, it is important not to drink alcohol while you are ill and for a month after the illness.

How long will I be sick?

The length of illness varies greatly from person to person. The symptoms of sore throat and fever usually go away in 7 to 10 days. The fatigue is the most persisting symptoms and can last for 2 to 3 months. Get regular rest as well as naps if you need them.

Does mono have any complications?

Mono can sometimes have complications. Possible complications include the following:

Strep Throat – Strep throat occurs at the same time in 8% of individuals with mono. Strep throat can be treated with antibiotics even though the antibiotics will not treat the virus causing the mono.

Liver Inflammation – Although not common, inflammation of the liver can occur. Sometimes it will be severe enough for ”jaundice” to develop which causes the eyes, skin, and urine to become abnormally yellow. Individuals with this “mono hepatitis” are usually more severely ill.

Rupture of the spleen – The most serious possible complication is that the spleen can enlarge and rupture. A ruptured spleen is a medical emergency and requires immediate medical care.

The spleen is located in the upper part of the abdomen on the left side, under the ribs. It functions to store and filter blood. The spleen becomes enlarged 50% to 100% of the time with mono, although often it is not enough that it can be felt on exam. It usually returns to normal in 4 weeks.

Rupture of the spleen is rare, occurring in only 0.1% to 0.2% of individuals with mono. The enlargement of the spleen makes it more fragile. Half of time the spleen ruptures due to trauma (direct blows to the spleen) or too much physical exertion and the other half occur for no apparent reason.

The symptoms of a ruptured spleen include pain in the upper left abdomen and radiating to the top of the left shoulder. The pain gets worse with breathing in and then spreads quickly over the entire abdomen. If this happens, get medical attention immediately.

What about sports?

The most important treatment for mono is to rest, eat well, and take care of yourself. You will have less strength and endurance as with any viral illness. In addition, too much physical activity, especially vigorous activity, increases your risk of rupturing your spleen. Almost all cases of the spleen rupturing due to mono occur between 4 and 21 days of the onset of symptoms.

You will need to talk with your health care provider regarding the specific recommendations for you. The usual recommendations are no vigorous activity for 21 days (this includes weight-lifting and playing sports). If the spleen is not enlarged, you can return to “easy” activity such as jogging, swimming, cycling after 21 days. If the spleen is not enlarged or tender, you can return to non-contact sports in one month. Talk with your health care provider about when you can return to contact sports or more vigorous activities such as football, hockey, rugby, baseball, basketball, judo, diving, karate, etc.)

Can I get Mono Again?

There is little evidence of repeated episodes of mono and generally, individuals only get mono once in their lifetime.

Written By Dr. Eilers Student Health Center Physician