My son was diagnosed w mono & strep C on May 10 & given 500 mg of Pennicillin (penicillin) 4x/day for 10 days. On May 29 he was diagnosed w strep C again & given 300 mg Clindamycin 3x/day for 10 days. On June 18 he was diagnosed w strep C again & given 300 mg of Cefdinir 2x/day for 10 days. On July 3 he was diagnosed w strep C again & given 875 mg Augmentin 2x/day for 10 days.
Each time he was cultured & each time responded positively immediately to medicine. He was given a blood test for mono which was positive on May 10 also.
In the circumstance you describe of Infectious Mononucleosis (IM it is not uncommon to have associated bacteria, including Strep C. It is at times difficult to be certain that these bacteria represent actual infection or are just present(but not causing disease), perhaps as a consequence of the IM. This distinction is not always an easy one. One clue would be the association symptoms and signs, that worsen when your son’s throat is culture positive. In the absence of any clinical deterioration when the Strep C is present, further attempts of the bacterium might not be warranted and it is possible that the Strep C will not be permanently eliminated until the IM resolves.
However, given the apparent response to antibiotics followed by recurrence, this might be a good time to request consultation with an Infectious Disease Specialist, especially if he feels or appears ill after antibiotic therapy is discontinued.