I'm adding a new post because I heard back very quickly from Dr. Robert Frenck, the first author of the study I mentioned in the last post. He helped me understand the study a bit better.
The study started about 10 years ago and basically represents a pre-pandemic view of group A streptococcal (GAS) epidemiology. It was carried out in outpatient clinics rather than emergency departments or urgent care centers. I was mistaken in how I described enrollment; the children actually entered the study during a well visit and then had subsequent well and sick visit monitoring. I had thought the sick visit was the trigger for enrollment.
The above features make the results more applicable to primary care practitioners, though it's hard to predict whether GAS epidemiology will look different in the post-pandemic era.
Dr. Frenck mentioned some key takeaways from his report: "The biggest thing we were able to re-show is the very high prevalence of GAS in the pharynx of children. I think it shows that many diagnoses of “strep throat” really are detecting colonization. Unfortunately, we did not find a good lab marker to reliably diagnose strep throat."
We're going to hear more about GAS vaccines in the next few years. I'm pretty sure vaccine manufacturers are deep into meetings with FDA staff to devise the best approach for an effectiveness study.