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.  I mention this only because this where I did my medical training and I worked in the lab with this group for about 3 years.  Let me assure you these guys are some of the most famous researchers in the field of infectious disease.

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

Almost 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.

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.

References

American Journal of Diseases in Children

This is a link to the article mentioned above.