Antibiotics to eradicate Streptococcus pyogenes pharyngeal carriage in asymptomatic children and adults: A systematic review

Streptococcus pyogenes (S. pyogenes) is a Gram-positive bacteria which causes a spectrum of diseases ranging from asymptomatic infection to life-threatening sepsis. Studies report up to 2000 times greater risk of invasive S. pyogenes disease in close contacts of index cases within 30-days of symptom onset. Despite this, there is variability in the management of asymptomatic carriage of S. pyogenes and those at risk of secondary cases of invasive S. pyogenes infection. Objective: Our systematic review assessed the efficacy of different antibiotic regimens used for eradication of S. pyogenes from the pharynx in asymptomatic individuals. Methods: We searched Pubmed, EMBASE (1974-), OVID Medline (1948-) and the Cochrane CENTRAL registry. We included randomised controlled trials (RCTs) with asymptomatic participants with > 50% with pharyngeal cultures positive with S. pyogenes at baseline. Only studies with microbiological methods including culture (+/- polymerase chain reaction, PCR) were included. We included studies published in English. Each included study was assessed by two independent reviewers for data extraction and risk of bias. Results: Of 1166 unique records identified, three RCTs were included in the review. Two of the three included RCTs found oral clindamycin for 10-days was the most efficacious regimen, compared to intramuscular benzathine penicillin G followed by 4 days of oral rifampicin, or monotherapy using benzathine penicillin, phenoxymethylpenicillin or erythromycin. Two RCTs were assessed as being at high risk of bias, with the third study demonstrating low/some risk of bias. Conclusions: Current available evidence for the optimal antibiotic in eradicating pharyngeal S. pyogenes carriage is limited. Future RCTs should include penicillin, first-generation cephalosporins, rifampicin, macrolides (such as azithromycin) and clindamycin. (c) 2024 Published by Elsevier Ltd on behalf of The British Infection Association. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).