What Infections Can You Get From Kissing Someone?

We tend to associate sexually transmitted diseases (STDs) and infections (STIs) with vaginal, anal, and oral sex. But it is also possible to get sick after kissing someone, although chances are relatively much lower.

Here are four types of infections that can be transmitted through mouth-to-mouth contact with an infected person.

1. Herpes

Oral herpes, often referred to as cold sores, is caused by herpes simplex virus type 1 (HSV-1). According to experts, it is the most common infection spread through kissing. Women are said to be more susceptible than men to the virus.

The risk of transmission is also higher if there are any sores in the mouth or on the lips. Medical experts advise taking a quick look at the mouth area before kissing someone as herpes-related blisters and sores are quite noticeable.

2. Gingivitis

Gingivitis, an inflammation of the gums, is a mild form of gum disease. The bacteria responsible for the inflammation can potentially be passed on through contact with infected saliva.

"Kissing someone who has gum disease or cavity-causing bacteria can cause someone else who previously had a low concentration of 'bad' bacteria to 'catch' dental problems," said California-based dentist Mark Burhenne. 

He added that maintaining good oral hygiene (brushing twice a day, flossing, etc.) is the best way to protect yourself against these kinds of bacteria. 

3. Mononucleosis

Infectious mononucleosis, sometimes known as "the kissing disease," is caused by the Epstein-Barr virus (EBV). In addition to kissing, it can be passed on through coughing, sneezing, sharing toothbrushes or glasses, etc. 

Once infected, a person can experience symptoms like extreme fatigue, sore throat, fever, loss of appetite, and swollen lymph glands. It is considered less contagious than a cold and is most likely to affect younger people between 15 to 30 years of age. 

According to the Mayo Clinic, EBV can remain in a person's saliva for months after the infection. It is advisable to avoid kissing people and sharing food or drinks until several days after the fever has subsided.

4. Syphilis

While the chances are quite low compared to transmission via sexual activity, there is a minor chance of contracting this infection by kissing someone. "Syphilis is a highly infectious condition, and one of its hallmarks is the development of sores in the mouth," said Louisiana​-based OB-GYN Antonio Pizarro.

The sores are usually round and open which might help the bacteria (Treponema pallidum) spread through close contact. "Any time there's an open sore and/or blood present, theoretically, an infection could be transmitted orally," Pizarro added.

According to the Centers for Disease Control and Prevention (CDC), syphilis cases have been on the rise in the United States, increasing by almost 18 percent from 2014 to 2015.