
Infectious mononucleosis, also called mono, is a contagious disease most commonly caused by the Epstein-Barr virus (EBV). It’s unclear how long someone with mono is contagious, although they are definitely contagious while they have symptoms.
However, if you are infected with the virus, it may take 4-8 weeks for symptoms to appear (incubation period). During this time, you can spread the infection to other people even if you may not be aware that you are sick (asymptomatic viral shedding). Once symptoms appear, they can last 2-4 weeks or even longer.
What about after symptoms subside? Studies suggest that you can be contagious for up to 6 months even after your symptoms go away.
This is because once you are infected, the virus stays dormant, or inactive, in your body for the rest of your life. The dormant virus can become active at any given time and find its way into your saliva, causing you to spread the virus to others without your being aware of it.
How is mono spread?
Mono is often called “kissing disease” as the virus commonly spreads through saliva. Sharing glasses or eating utensils can therefore spread the infection.
In some cases, mono can also spread through blood and semen during sexual contact, blood transfusions, and organ transplantations.
Since it is quite tricky and difficult to know when a person is contagious, it’s important to take protective measures such as washing your hands frequently and avoiding sharing toothbrushes, drinks, and eating utensils with others.
What are signs and symptoms of mono?
Signs and symptoms of mono include:
- Fever
- Sore throat, causing swallowing difficulty
- Extreme tiredness or fatigue
- Headache
- Body aches and pains
- Swollen lymph nodes (glands) in the neck and armpits
- Enlarged liver or spleen or both
- Rash
- Inflammation of the liver, causing yellowing of the skin and eyes (jaundice) in some people
- Liver and spleen enlargement (in rare cases)
Symptoms may appear after 4-8 weeks of getting exposed to the infection.
Generally, symptoms start to subside in 2-4 weeks, although fatigue may last much longer. And even after fatigue subsides, the liver or spleen or both may stay enlarged for a long time. For some people, symptoms may last for as long as 6 months.
How is mono diagnosed?
To diagnose mono, your doctor may take your medical history and perform a detailed medical examination. Generally, lab tests are not required for people who are showing typical symptoms. For people who don’t show any definitive symptoms, a blood test may be done to confirm a diagnosis. Typical findings in a blood test may show:
- Increased white blood cells or WBCs (lymphocytes)
- Unusual looking WBCs (atypical lymphocytes)
- Reduced number of neutrophils (a type of WBCs) or platelets
- Abnormalities in liver function test (LFT)

QUESTION
Bowel regularity means a bowel movement every day. See AnswerAuwaerter PG. Patient education: Infectious Mononucleosis (mono) in Adults and Adolescents (Beyond the Basics). UpToDate. https://www.uptodate.com/contents/infectious-mononucleosis-mono-in-adults-and-adolescents-beyond-the-basics
Top How Long Is a Person Contagious With Mono Related Articles
How Long Does It Take To Heal From Mononucleosis?
Infectious mononucleosis, also called “mono,” is a contagious infection most commonly caused by a herpes virus called Epstein-Barr (EBV). Teenagers and young adults are more commonly affected by mononucleosis.Mono (Infectious Mononucleosis)
Infectious mononucleosis is a virus infection in which there is an increase of white blood cells that are mononuclear (with a single nucleus) "Mono" and "kissing disease" are popular terms for this very common illness caused by the Epstein-Barr virus (EBV).Infectious Mono Pictures
Infectious mononucleosis. Swollen tonsils that appear red and with white lesions that may be oozing pus are a hallmark of infectious mononucleosis. It is considered highly contagious and is usually caused by the Epstein-Barr Virus (EBV). Mono spreads through saliva and therefore is sometimes called “kissing disease.”Mononucleosis Slideshow
What is mononucleosis? How do you get mono? What does a mono rash look like? Learn about mono symptoms, treatment, and diagnosis. Discover how mononucleosis is caused by the Epstein Barr virus.Is Mononucleosis (Mono) Contagious?
Mononucleosis (mono) is caused by the Epstein-Barr virus and can be transmitted by an infected person's saliva. Mono symptoms and signs include rash, enlarged spleen, swollen lymph nodes, fever, sore throat, and fatigue.Mononucleosis Causes
Mononucleosis is a contagious (but not highly contagious) disease, mostly caused by Epstein-Barr virus (EBV) infection. Hence, it is also known as infectious mononucleosis.