Does Saliva Have Health Risks? 3 Ways Germs Can Spread

Find out which viruses and bacteria can become someone else's problem
Does Saliva Have Health Risks? 3 Ways Germs Can Spread

Your mouth is home to hundreds of different microorganisms. What happens when you’re exposed to someone else’s saliva?

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“The risk of transmitting infectious organisms to someone else through saliva is very low,” says Michael Benninger, MD. “Saliva has antibodies and enzymes that decrease the risk of contagions.”

That said, you’d be surprised by what can work their way from your saliva into your nose, throat and lungs:

  • Rhinovirus (colds)
  • Flu virus
  • Epstein-Barr virus (mononucelosis, or mono)
  • Type 1 herpes (cold sores)
  • Strep bacteria
  • Hepatitis B and hepatitis C
  • Cytomegalovirus (a risk for babies in the womb)

“Some of the new viruses, such as ebola virus and bird flu, are also a concern,” says Dr. Benninger. Contrary to popular belief, however, the AIDS virus (human immunodeficiency virus, or HIV) is not transmitted through saliva.

Here are three ways you can accidentally transmit infection through saliva:

1. Kissing

It easy to exchange infectious organisms during a kiss through your saliva. They can find their way from your mouth into your throat and lungs. That’s why mono is called the “kissing disease.”

“You can spread colds and flu by kissing, although cold viruses usually spread by touching a contaminated surface and then your nose,” says Dr. Benninger.

Your saliva typically protects you against bacteria in your partner’s saliva. (There will be more bacteria when oral hygiene is poor.)

But one bacteria that can be transmitted is MRSA, the serious staph infection.

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Also, if you have a cold sore, kissing someone can spread the herpes 1 virus.

“Despite this, there is lots of kissing going on, and very few infections,” says Dr. Benninger.

Related: Strep or Sore  Throat? Best Ways You Can Tell

2. Sharing toothbrushes

Ever forget a toothbrush and borrow your partner’s? The American Dental Association advises against this practice.

“Toothbrushes may cause microtrauma. Someone else’s saliva can come in contact with tears in your mucous membrane and transmit infection,” explains Dr. Benninger.

Sharing toothbrushes is especially risky if you have a weakened immune system.

Have a cold, sore throat or other virus? Keep your toothbrush from touching the family toothpaste and others’ toothbrushes.

RELATED: Boil, Soak or Pitch It? 4 Tips for a Clean Toothbrush

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3. Sharing mouthguards

Mouthguards protect your teeth, mouth and jaw during sports, and help keep you from grinding your teeth at night.

You can get stock mouthguards from a sporting goods store, “bite and boil” mouthguards from a drugstore, or custom-made mouthguards from your dentist.

Whatever type you use, mouthguards, which are porous, should never be shared. A 2007 study, reported in General Dentistry, found that mouthguards harbor bacteria, yeasts and molds.

“Someone else’s mouthguard may fit very poorly and cause microtrauma,” says Dr. Benninger. This can expose your mucous membranes to infection.

If you wear a mouthguard, be sure to:

  • Brush your  teeth before inserting it
  • Clean it whenever you brush your teeth
  • Store it in a case
  • Avoid chewing on it

RELATED: Does My Child Need a Mouthguard for Sports?

The bottom line

“The risk of saliva transmitting disease is very small. That means kissing is safe under most circumstances — thank goodness!” says Dr. Benninger.

“That said, most people would prefer to choose whom they want to share saliva with.”

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