how do you get mono

You get mononucleosis (“mono”) primarily through contact with infected saliva, which is why it is commonly called the “kissing disease”. The illness is most often caused by the Epstein-Barr virus (EBV), though other viruses like cytomegalovirus (CMV) can also trigger it.

Common Ways Mono Spreads

Any activity that transfers bodily fluids—especially spit—from an infected person can pass the virus.

• Kissing. Direct mouth-to-mouth contact is the most well-known way to catch the virus.
• Sharing drinks and food. Sipping from the same cup, water bottle, or straw, or taking bites from the same food transfers saliva.
• Sharing personal items. Using someone else’s eating utensils, toothbrush, or lip balm can expose you to the virus.
• Coughing or sneezing. Tiny droplets of saliva expelled into the air can reach people nearby during close contact.
• Other bodily fluids. Less commonly, the virus spreads through blood or semen during sexual contact, blood transfusions, or organ transplants.

Why It Spreads Easily Without Notice

According to the Centers for Disease Control and Prevention (CDC), EBV is very common and hard to contain for a few key reasons:

• Long incubation period. Symptoms take 4 to 7 weeks to show up after exposure, meaning people can spread the virus before they even realize they are sick.
• Asymptomatic carriers. Many people—especially young children—carry and shed the virus without ever developing noticeable symptoms.
• Lingering contagiousness. The virus can stay active in a person’s saliva for months after they recover and feel completely fine.

Who Is Most Likely to Get Sick?

While the Mayo Clinic notes that most adults have already been exposed to EBV in childhood and built up immunity, teenagers and young adults (such as high school and college students) are the most likely to develop full mono symptoms when they are first exposed.