You Decide: What is a Strep Carrier?

Understanding what it means to be a Strep carrier is critical if you want to understand the management of sore throat.  It is especially critical for Smart Parents to understand so they can be vigilant to make sure their children are not needlessly exposed to antibiotics and their side-effects.  While most physicians are aware that some kids are Strep carriers, it does not seem to influence their practice much.  As a result, many kids who clearly have the common cold as the source of their sore throat, are often tested and treated from Strep.  In my mind, this practice is irrational.  Let me explain, then… You Decide.

What is a Strep Carrier?

As I mentioned before, the bacteria that causes Strep throat lives in our mouth and on our skin.  The same thing goes for other things like Staph and some of the bacteria that causes pneumonia.  Most of the time, these bacteria are completely harmless.  However, for reasons that no one really understands, these bacteria sometimes cause infection.  When Staph causes infection it is normally an infection in the skin.  When Strep causes infection it may be in the throat or in the skin.  Infection in the throat, caused by Strep, is what we commonly call Strep throat.

This brings to mind a few questions:

  1. How common is it to have Strep in your mouth?
  2. How often do people who have Strep in their mouth go on to get an infection?
  3. What happens to the Strep if we give antibiotics?

The Answers

There was a great article that addressed these very questions written by a group of researchers in Dallas at the University of Texas Southwestern.  In their study, they decided to take a group of normal healthy kids, test them for Strep, and see what they found.  Now, remember these are kids that have nothing wrong with them – no fever, sore throat, or anything else.  Then they went on to follow these kids to see if they developed Strep throat.  Then they gave them antibiotics to try and kill the Strep and retested them a few days after the antibiotics were finished.  What they found was very interesting

How common is it to have Strep in your mouth?

The researchers tested almost 1400 kids between the ages of 3 months and 14 years of age.  Depending on the age groups, as many s 8.3% of normal healthy children had Strep in their mouth when they were tested.  That means almost 1 in 10 children are Strep carriers.  They have Strep in their mouth but it is not causing an infection.  This leads to the next obvious question…

How many of these kids developed Strep throat?

The researchers were able to follow up with about 2/3 of the kids that had a positive Strep test.  NONE of these kids has any evidence of Strep throat at follow up.  So it appears that having Strep in your mouth does not make it any more likely that the average person will get a Strep infection.  The next question is this…

What happens if we give antibiotics anyway?  Will it make the Strep go away?

They gave the kids with a positive Strep tests a 10-day course of antibiotics and then retested them a few days after stopping the antibiotics.  The results… just over 25% of the kids had the Strep back in their mouth as soon as the antibiotics were stopped.

In summary

As many as 1 in 10 kids have Strep in their mouth which is NOT causing an infection.  We call these children Strep carriers.  Children who are Strep carriers are no more likely than anyone else to develop Strep throat.  Even if you give these kids antibiotics to try and eliminate the Strep from their mouth, it will come right back in about 25% of kids.

Critical Implication

This is why it is critical to understand the signs and symptoms of Strep throat.  Imagine that someone brings their child to see me in the ER complaining of low grade fever, runny nose, nasal congestion, sore throat, and cough for the past 2-3 days.  When I examine the patient there is no pus on the tonsils and there is no swelling in the neck glands.  Based on the signs and symptoms, this patient clearly has the common cold.  However, there is about a 1 in 10 chance they are also a Strep Carrier.  So if I test this child for Strep, there is about a 1 in 10 chance it will be positive.  Then, I will probably feel compelled to treat that patient with an antibiotic.  Since the patient just has a cold (which is caused by a virus) the antibiotic will not improve any of the signs and symptoms of the cold.  However, the child will be exposed to all of the side-effects of the antibiotic, some of which can be severe.

Based on this information, I can only draw one rational conclusion.  All patients that complain of a sore throat do not need a Strep test. If they have most, or all, of the signs and symptoms of Strep throat, then it makes sense.  If, however, sore throat is the only symptom of Strep throat they have, and clearly have all the signs and symptoms of a cold (like runny nose, nasal congestion, and cough), then I cannot make a rational argument for testing these kids for Strep.  In my mind, it is wasteful and will lead to needless antibiotics treatment.

Of course, this is just my opinion.  For you and your family… You Decide.

I am NOT your doctor

Please let me clear to those who may be reading this site and thinking of making medical management decisions based on this information… I am not your doctor.  In general it is a bad idea to make any medical decisions based solely on anything read on the internet.  I have presented a framework for you to have an intelligent discussion with your own doctor.  In many cases, you and your doctor will agree that a strep test is not indicated.  In some cases you may decide to go ahead test and treat.  Either way the decision should be made in consultation with your own doctor who has the opportunity to consider the specifics of your child and also perform a careful physical examination.

What’s Next

It is important to understand a few of the complications of Strep throat, like Rheumatic Fever and throat abscess.  Both are very UN-common, but two of the things cited by most physicians that insist on testing and treating for Strep anytime someone complains of sore throat.


American Journal of Diseases in Children

This is a link to the article mentioned above.


  1. Mu daughter started having strep symptoms 4 months ago. Although the doc did not see the signature signs in her throat (white pus an swollen glands), he tested her anyways and it came out positive. She was treated with her first round of antibiotics and the sore throat went away. She however continues to have a very low grade (99.4) fever on and off, so she was tested for strep again. To make a long story short, she’s been tested five times with a low on and off grade fever and each time the culture came back positive. She never had the white pus or swollen glands. The low fever was the only symptom and no sore throat. They continue to prescribe more antibiotics and we just saw the ENT and he says to continue antibiotics for 21 days (she’s already been on them for 30 days) and if she tests positive after all of that, then she needs her tonsils out, carrier or not. I feel like my only choices are to pump her wih more meds and then give her surgery, which I’m apprehensive about. What are your thoughts?

  2. I would suggest going to see a pediatric infectious disease doctor before you subject your child to this surgery. Google the nearest pediatric medical center associated with a medical school. Make an appointment with the pediatric (adult doctor is not the same) infectious disease specialist.

  3. The reason he probably has MRSA is because it (MRSA) is resistant to all those antibiotics he has been taking. You see, when you start taking lots of antibiotics it kills all the helpful bacteria and makes room for those bacteria (like MRSA) that are resistant. Why is he even being tested for staph? Staph has nothing to do with a sore throat and nothing to do with the tonsils. Staph hangs out in your nose and on your skin. There is no such thing as “staph throat.” I would go see the ENT to find out why his tonsils are asymmetric but I would be very cautious about taking them our simply because he has a positive strep test or is a MRSA carrier.

  4. Strep at birth is called Group B Strep (GBS). Strep in your mouth is Groups A Strep (GAS). They are different and completely unrelated.

  5. Physicians Insanity!!! Really ANOTHER surgery for a child with no symptoms of strep infection. Get a second opinion from a PEDIATRIC ENT that is associated with the nearest medical school.

  6. The available evidence suggests that those kids who are around strep carriers are no more likely than anyone else to get a strep infection.

  7. I suspect my child is a strep carrier. He has tested positive numerous times each year but is lacking in physical symptoms…no fever, no swollen glands, just a slight sore throat. Pediatrician always treats him with antibiotics each time based on the positive strep test results. I discussed with her the possibillity of my child being a carrier. So she tested him immediately following this last round of antibiotics and he tested negative so she says he cannot be a carrier because a carrier will always test positive even right after antibiotic therapy. Is this true?

  8. THis is false. About 25% of kids will get strep back in their mouth as soon as the antibiotics are stopped. Your child IS a carrier if he is asymptomatic AND has strep in his mouth.

  9. Nander Bravo says:

    Hello Dr. Raynolds.
    We have a five year old son who used to get strep throat almost every other month. So, his pediatrician suggested a tonsillectomy. We went to an ENT, and got his tonsils removed about two months ago. However, about a week ago he started to cough a lot along with runny nose. My wife took him to the doctor and said he tested positive for strep. How could this be? Should we be concern about it? They said he might be a carrier, and my wife and I are just concern for his health. We though that after having his tonsils removed he would be much better. What is your opinion about it?
    Thank you

  10. Having the tonsils removed will not affect if your child gets strep or not. It will only make the symptoms less severe. Cough and runny nose does not sound like strep to me – it sounds like a cold and I would not even test a child like that for strep. There is a good chance he is a carrier of strep – which means the test will be positive even if the symptoms are caused by something else – like the common cold. Antibiotics and tonsillectomy will have no effect on the likelihood of getting the common cold and no benefit to its treatment.

  11. Dr. Reynolds,
    My 4 1/2 year old daughter has extremely large tonsils. She had her adenoids removed 2 years ago because of sleep issues. She tested positive for Mono back in January. We waited to see if the tonsils would shrink due to the mono infection. They have actually grown since. In the past 5 months she has tested positive for strep 5 times. Sometimes she shows symptoms sometimes she doesn’t. Our ENT had us do a sleep study – this way it would give us a clear answer as to whether we should remove the tonsils or keep checking her out. She has sleep apnea and are waiting to get the tonsils removed in September. The ENT did say he thinks she might be a carrier because of the frequency of her strep infections. I know she will get less severe symptoms of strep once the tonsils are removed. How do we know when to really treat strep if she is in fact a carrier after the surgery?

  12. I only test and treat the strep when there are symptoms of strep – high fever, sore throat, and an exam consistent with strep, in the absence of signs/symptoms of the common cold (runny nose, cough, etc.). Getting tonsils out in the setting of sleep apnea is reasonable. A secondary benefit is that any subsequent throat infections (strep or otherwise) will be less severe, although the frequency will probably still be the same.

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