Abx in Strep throat absolutely does more harm than good.
There really is no excuse to use them in any patient unless they're immigrants or you're in the middle of an ongoing rheumatic fever epidemic.
Looking at the numbers:
About 14 million per year sore throat visits in the US.
About 80-85% of these are viral pharyngitis.
Nothing new or exciting. Yet.
Now, Streptococcal pharyngitis constitutes the remainder of cases = about 15% of total sore throat visits.
Thus, about 2 million strep throat visits per year in the US.
So, on to
acute rheumatic fever (ARF):
Incidence from the CDC in 1992:
0.1/100,000 or 1 in 1,000,000
Why 1992 do you ask?
Because they stopped tracking it in 1992 because it stopped being a public heath threat
And by the way, the incidence of ARF here in the US has been decreasing since the 1800s, long before we started using Abx.
So, if the incidence still 1/100,000,000 then thats about 300 cases/year of ARF
But, only 30% of ARF patients go to the doctor, thus we only see about 100/year
Thus, 2 million strep throat visits per year / 100 ARF visits per year = 1 in 20,000 strep throat cases go on to become ARF
Now remember, Abx don’t prevent ARF, they only reduce your risk by 50%.
Thus, with a relative risk reduction (RRR) of 50%, your
Number Needed to Treat (NNT) for ARF is now 40,000
Or in layman’s terms,
you need to treat 40,000 cases of strep throat to prevent 1 case of ARF.
Now lets compare that to some adverse effects of Abx for strep throat:
about 1 in 5 patients get diarrhea = Number Needed to Harm (NNH) of 5
about 1 in 20 patients get a rash = NNH of 20
about 1 in 10,000 patients have a fatal anaphylactic reaction = NNH of 10,000
And this one most people don’t know about:
Because you don’t adequately develop protective antibodies when treated with Abx compared to placebo,
patients treated with Abx have an 18% absolute higher risk of getting another strep throat. Not Relative, Absolute. Thus, patients treated with Abx now have a 1 in 6 chance of getting another strep throat which of course also increases your chances of getting ARF = NNH of 6
Now, taking all those above numbers into account,
For every 1 ARF you prevent, you cause:
8,000 diarrheas
7,000 strep throats
2,000 rashes
and kill 4 people from anaphylactic reactions
...Stay thirsty my friends.
Sources:
1.
http://smartem.org/podcasts/treatment-acute-pharyngitis
2.
https://www.emrap.org/episode/2013/february/penicillinin
3.
http://www.epmonthly.com/department...antibiotics-for-strep-do-more-harm-than-good/
4.
http://www.epmonthly.com/department...iotics-for-strep-addressing-readers-concerns/