[The year my daughter was 5 she had strep throat 4 times, 2 of those requiring 2 round of antibiotics EACH. That was SIX ROUNDS of antibiotics in a year.
Here's a tip I found out the hard way. A few years ago in the summer I got strep, did the penicillin route, knocked it out. About two days after finishing the antibiotic, I got it AGAIN! I'm thinking, wth is going on here? I go back to the doc and she asks me a question and I felt like slamming my head against the wall. She asked if I'd replaced my toothbrush. well DUH! Of course I didn't because it wasn't old, but the stupid thing harbors bacteria. Any time you get sick, throw that puppy out and get a new one. I felt like such a dope, how could I not know that one. So...next time anyone in your house gets a virus like that, or strep, or the stomach bug, grab new toothbrushes for everyone affected. I'm so sorry if your doc didn't tell you this and maybe instead subjected your sweet child to unnecessary antibiotics and illness, when this could've been the culprit. HTH