Agreement between rapid antigen detection test and culture for group A streptococcus in patients recently treated for pharyngotonsillitis - a prospective observational study in primary care

Abstract Objective The aim was to compare rapid antigen detection test (RADT) and throat culture for group A streptococci (GAS) among patients recently treated with penicillin V for GAS pharyngotonsillitis. Design and setting The study was a secondary analysis within a randomized controlled trial comparing 5 versus 10 days of penicillin V for GAS pharyngotonsillitis. Patients were recruited at 17 primary health care centres in Sweden. Subjects We included 316 patients ≥ 6 years of age, having 3–4 Centor criteria, a positive RADT and a positive throat culture for GAS at inclusion, and also having a RADT and throat culture for GAS taken at a follow-up visit within 21 days. Main outcome measures RADT and conventional throat culture for GAS. Results This prospective study showed 91% agreement between RADT and culture at follow-up within 21 days. Only 3/316 participants had negative RADT with a positive throat culture for GAS at follow-up, and 27/316 patients with positive RADT had a negative culture for GAS. Log rank test did not reveal any difference in the decline over time of positive tests between RADT and throat culture (p = 0.24). Agreement between RADT and throat culture for GAS at the follow-up was not associated with treatment duration, number of days from inclusion until follow-up, throat symptoms at follow-up, gender, or age. Conclusion RADT and culture for GAS agreed to a high extent also after recent penicillin V treatment. RADT for GAS means a low risk for missing the presence of GAS. KEY POINTS Testing for group A streptococci (GAS) before antibiotic treatment can reduce antibiotic prescription for pharyngotonsillitis. It has been proposed that rapid antigen detection tests (RADT) for group A streptococci after recent penicillin V treatment may be falsely positive due to possible persisting antigens from non-viable bacteria. The decline of the presence of GAS was similar between RADT and conventional throat culture in patients who had recently completed penicillin V treatment for GAS pharyngotonsillitis RADT for GAS is useful in identifying the presence of GAS after recent penicillin V treatment

[1]  R. Gunnarsson,et al.  What is the optimal strategy for managing primary care patients with an uncomplicated acute sore throat? Comparing the consequences of nine different strategies using a compilation of previous studies , 2022, BMJ Open.

[2]  P. Glasziou,et al.  Antibiotics for treatment of sore throat in children and adults. , 2021, The Cochrane database of systematic reviews.

[3]  Jérémie F. Cohen,et al.  Diagnostic accuracy of rapid nucleic acid tests for group A streptococcal pharyngitis: systematic review and meta-analysis. , 2021, Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases.

[4]  K. Buising,et al.  Antimicrobial Stewardship in General Practice: A Scoping Review of the Component Parts , 2020, Antibiotics.

[5]  Jérémie F. Cohen,et al.  Efficacy and safety of rapid tests to guide antibiotic prescriptions for sore throat. , 2016, The Cochrane database of systematic reviews.

[6]  S. Mölstad,et al.  Penicillin V four times daily for five days versus three times daily for 10 days in patients with pharyngotonsillitis caused by group A streptococci: randomised controlled, open label, non-inferiority study , 2019, BMJ.

[7]  L. Donato,et al.  Assessment of Test Performance and Potential for Environmental Contamination Associated with a Point-of-Care Molecular Assay for Group A Streptococcus in an End User Setting , 2018, Journal of Clinical Microbiology.

[8]  N. Adriaenssens,et al.  Antibiotic prescribing in relation to diagnoses and consultation rates in Belgium, the Netherlands and Sweden: use of European quality indicators , 2017, Scandinavian journal of primary health care.

[9]  A. Schilder,et al.  Antibiotic prescribing in patients with self-reported sore throat , 2016, The Journal of antimicrobial chemotherapy.

[10]  R. Gunnarsson,et al.  Point of care testing for group A streptococci in patients presenting with pharyngitis will improve appropriate antibiotic prescription , 2016, Emergency medicine Australasia : EMA.

[11]  Marc Mendelson,et al.  The World Health Organization Global Action Plan for antimicrobial resistance. , 2015, South African medical journal = Suid-Afrikaanse tydskrif vir geneeskunde.

[12]  Jérémie F. Cohen,et al.  Rapid-antigen detection tests for group a streptococcal pharyngitis: revisiting false-positive results using polymerase chain reaction testing. , 2013, The Journal of pediatrics.

[13]  E. Bingen,et al.  Effect of clinical spectrum, inoculum size and physician characteristics on sensitivity of a rapid antigen detection test for group A streptococcal pharyngitis , 2013, European Journal of Clinical Microbiology & Infectious Diseases.

[14]  R. Gunnarsson,et al.  In primary health care, never prescribe antibiotics to patients suspected of having an uncomplicated sore throat caused by group A beta-haemolytic streptococci without first confirming the presence of this bacterium , 2012, Scandinavian journal of infectious diseases.

[15]  A. Bisno,et al.  Clinical Practice Guideline for the Diagnosis and Management of Group A Streptococcal Pharyngitis: 2012 Update by the Infectious Diseases Society of America , 2012, Clinical infectious diseases : an official publication of the Infectious Diseases Society of America.

[16]  Martin Chalumeau,et al.  Spectrum and Inoculum Size Effect of a Rapid Antigen Detection Test for Group A Streptococcus in Children with Pharyngitis , 2012, PloS one.

[17]  P. Little,et al.  Guideline for the management of acute sore throat. , 2012, Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases.

[18]  I. Petersen,et al.  Antibacterial prescribing in primary care. , 2007, The Journal of antimicrobial chemotherapy.

[19]  J. Carapetis,et al.  The global burden of group A streptococcal diseases. , 2005, The Lancet. Infectious diseases.

[20]  P. Hjortdahl,et al.  Which is the best method to trace group A streptococci in sore throat patients: culture or GAS antigen test? , 2004, Scandinavian journal of primary health care.

[21]  Michael A. Gerber,et al.  Rapid Diagnosis of Pharyngitis Caused by Group A Streptococci , 2004, Clinical Microbiology Reviews.

[22]  Warren J McIsaac,et al.  Empirical validation of guidelines for the management of pharyngitis in children and adults. , 2004, JAMA.

[23]  P. Glasziou,et al.  Antibiotics for sore throat. , 2004, The Cochrane database of systematic reviews.

[24]  J. Dale,et al.  Accuracy of rapid strep testing in patients who have had recent streptococcal pharyngitis. , 2002, The Journal of the American Board of Family Practice.

[25]  L. Rubin,et al.  APPARENT FALSE POSITIVE DETECTION OF GROUP A STREPTOCOCCUS ANTIGEN RESULTING FROM PHARYNGEAL INFECTION WITH A NONHEMOLYTIC STREPTOCOCCUS PYOGENES , 2000, The Pediatric infectious disease journal.

[26]  H. Davies,et al.  Evaluation of the Strep A OIA assay versus culture methods: ability to detect different quantities of group A Streptococcus. , 1999, Diagnostic microbiology and infectious disease.

[27]  J Howland,et al.  Effects of a rapid antigen test for group A streptococcal pharyngitis on physician prescribing and antibiotic costs. , 1990, Archives of internal medicine.

[28]  P. Beach,et al.  Group A Streptococcal Rapid Test , 1989, Clinical pediatrics.

[29]  M. Gerber,et al.  STREPTOCOCCAL ANTIGEN IN THE PHARYNX AFTER INITIATION OF ANTIBIOTIC THERAPY , 1987, The Pediatric infectious disease journal.

[30]  R M Centor,et al.  The Diagnosis of Strep Throat in Adults in the Emergency Room , 1981, Medical decision making : an international journal of the Society for Medical Decision Making.