@Benjispruce You may be right. I've only once heard it referred to as Strep throat here, so I assumed it's a specific form of bacterial tonsillitis.
My understanding (not a medic) is that strep throat has different forms so different ones may need different antibiotics, which is why you swab for it. I think strep A (or possibly one form of step A!) can be associated with Scarlet Fever for example.
I know that sometimes ds has had an infection that has kept on returning, for his ears or throat. After 3-4 times recurring they've done a swab and chosen the antibiotics accordingly and given him double the length, which seems to sort it.
He's also had antibiotic resistant ear infections which have looked like they're initially responding to the antibiotics and then returned about 3-4 days into the course with vengeance.