My daughter had recurrent strep years ago. The pediatrician wanted her to have her tonsils out, but I refused. We cultured the family's throats, then the cats' to see if maybe someone was a carrier. What a surprise it was to find that one of our cats carried strep and continued to culture positive even after treatment with antibiotics. My daughter was treated with clindamycin I think after many courses of penicillin. With more scrupulous hand washing after petting the cats, she has been strep-free for around 7 years now. Good luck! You may want to look into the possibility of pets (usually a dog) or another family member as a strep carrier since you had so many infections in such a short period of time.