Dear Ask The Doctor: My son has had steep throat. For a month. He has tested positive and was given 10 days of amoxicillan. Strep came back in 36 hours. He was reswabbed and tested positive. He was given 10 days of keflex. In 36 hours again it came back. He was re-swabbed and tested positive again. He is now on 20 days of augmentin. What could cause the strep from not going away? We have thrown out his toothbrush after each positive swab. My son is 12
Dear Carolyn: I can understand your concern because of failure of streptococcal tonsillopharyngitis to respond to antimicrobial therapy. No single antibiotic regimen eliminates GAS from the pharynx in 100 percent of cases. There are several potential explanations for antibiotic failure including :
i) Age of patient : Success with antibiotics is much lower in those aged 2 to 12 as compared to adults.
ii) Repeated exposure : Crowded living conditions encourage the transmission of GAS within the family, at work, at school, or in daycare settings.
iii) Presence of other bacteria : Staphylococcus aureus, Haemophilus influenzae, Moraxella catarrhalis, and beta-lactamase-producing anaerobic species.
iv) Streptococcus carriers : 30 percent of children infected with streptococcus go on to become carriers.
Some studies have shown that follow-up treatment with cefadroxil is a less costly and viable option in the treatment of strep throat after experiencing a penicillin/amoxicillin treatment failure.