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What is mononucleosis?

Mononucleosis, commonly known as "mono" or "the kissing disease," refers to a group of symptoms usually caused by the Epstein-Barr virus (EBV). This infection is infamous for the length of time it can last.

It’s estimated 90 to 95 percent of all adults have antibodies to EBV in their blood because the virus is so common. This means almost every adult has had an EBV infection. However, this doesn’t mean that everyone has had mononucleosis.

Many people develop EBV infections as children after age 1. In very young children, symptoms are usually nonexistent or so mild that they aren’t recognized as mono. Once you have an EBV infection, you aren’t likely to get another one. Any child who gets EBV will probably be immune to mono for the rest of their life.

However, plenty of children in the United States and other developed countries don’t get these infections in their early years. According to the U.S. Centers for Disease Control and Prevention, mono occurs 25 percent of the time when an adolescent or young adult is infected with EBV. For this reason, mono affects mainly high school and college students.

Most cases of mono are mild and resolve easily with minimal treatment.

Causes of mononucleosis

Infectious mono is spread by saliva transmission. You can become infected by kissing or sharing food, dishes, or eating utensils with someone who has mono. It usually takes four to eight weeks for symptoms to develop after you’re infected.

The best way to prevent mono is to avoid coming into contact with other people’s saliva. If you are infected, take precautions to avoid infecting anyone else.

High-risk groups for mononucleosis

The following groups have a higher risk for getting mono:

  • young people between the ages of 15 and 25
  • students
  • interns
  • nurses
  • caregivers
  • people on immunosuppressive drugs

Anyone who regularly comes into close contact with large numbers of people is at an increased risk for mono. This is why high school and college students frequently become infected.

The symptoms associated with mononucleosis

The following are the most common symptoms of mono:

  • fever
  • sore throat that gets worse
  • swollen glands (lymph nodes) in your neck, underarms, and groin
  • severe fatigue

Additional mono symptoms include:

Mono is hard to distinguish from other common viruses such as the flu. If your symptoms don’t improve after one or two weeks of home treatment such as resting, getting enough fluids, and eating healthy foods, see your doctor.

How mononucleosis is diagnosed

Because other, more serious viruses such as hepatitis A can cause symptoms similar to mono, your doctor will work to rule out these possibilities.

Initial exam

Once you visit the doctor, they’ll normally ask how long you’ve had symptoms. If you’re between age 15 and 25, your doctor might also ask if you’ve been in contact with any individuals who have mono. Age is one of the main factors for diagnosing mono along with the most common symptoms: fever, sore throat, and swollen glands.

Your doctor will take your temperature, and check the glands in your neck, armpits, and groin. Your doctor might also check the upper left part of your stomach to determine if your spleen is enlarged.

The monospot test

Lab tests are the second part of a doctor’s diagnosis. One of the most reliable ways to diagnose mononucleosis is the monospot test (or heterophile test). This blood test looks for antibodies —these are proteins your immune system produces in response to harmful elements. However, it doesn’t look for EBV antibodies. Instead, the monospot test determines your levels of another group of antibodies your body is likely to produce when you’re infected with EBV. These are called heterophile antibodies.

The results of this test are the most consistent when it’s done between two and four weeks after symptoms of mono appear. At this point, you would have sufficient amounts of heterophile antibodies to trigger a reliable positive response.

This test isn’t always accurate, but it’s easy to do, and results are usually available within one hour or less.

EBV antibody test

If your monospot test comes back negative, your doctor might order an EBV antibody test. This blood test looks for EBV-specific antibodies. This test can detect mono as early as the first week you have symptoms, but it takes longer to get the results.

Complete blood count

Sometimes your doctor will request a complete blood count. This blood test will help your doctor determine how severe your illness is by looking at your levels of various blood cells. For example, a high lymphocyte count often indicates an infection such as mono.

What the treatment options are for mono

Treatment for mononucleosis is very basic. It involves addressing your symptoms.

For the most part, this entails at-home treatment including:

  • getting a lot of rest
  • drinking a lot of fluids (Water is best.)
  • gargling with warm salt water for sore throat
  • eating warm chicken soup
  • using over-the-counter pain medication
  • taking prescription corticosteroids to help reduce throat and tonsil swelling

Once you’re infected with EBV, the virus will remain in your body in a dormant state indefinitely. So you can continue to test positive for the virus for the rest of your life after symptoms resolve. The virus can reactivate at times, but it rarely causes illness unless you have a weakened immune system.

If your symptoms get worse or you experience intense abdominal pain, contact your doctor. One of the complications of mono is a ruptured spleen, which is a life-threatening situation. A ruptured spleen will usually occur between 4 and 21 days after you begin to have symptoms. If your spleen ruptures, you’ll need emergency surgery to remove it.

Recovery from mono

Mononucleosis can be a debilitating disease. The majority of people who have mononucleosis recover within two to four weeks and can return to regular activities in two weeks.

The good news is that once you’ve gotten mono, you usually don’t have to worry about becoming sick with it again.

During your recovery, make sure to avoid contact sports or any other strenuous activity.

Content licensed from:

Written by: Shannon Johnson
Medically reviewed on: May 12, 2017: Elaine Luo, MD

This feature is for informational purposes only and should not be used to replace the care and information received from your health care provider. Please consult a health care professional with any health concerns you may have.
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