Rapid Antigen Detection Test Guides Antibiotic Use

The effect of clinical scores that predict streptococcal infection or rapid streptococcal antigen detection tests were compared with delayed antibiotic prescribing.

Sore throat is one of the respiratory infections for which there are several reasonable diagnostic strategies for targeting antibiotics and rapid streptococcal antigen detection tests (RADTs) are one of the commonest near patient tests in clinical use internationally. Clinical scores are also used to predict streptococcal infection used either alone or in combination with the antigen test.


Scientists at the University of Southampton (UK) recruited 631 patients with an acute sore throat and compared use of the FeverPAIN clinical score, with or without rapid antigen testing, with a delayed prescription, in which patients were told to pick up a prescription three to five days later if their symptoms did not settle or got worse. The FeverPAIN score includes fever in the past 24 hours, a pus infection, rapid attendance within three days, inflamed tonsils and no cough or cold symptoms.

The IMI test pack RADT (Inverness Medical; Bedford, UK) was used to detect Lancefield Group A Streptococcus based on in vitro performance and ease of use. The results showed that using the FeverPAIN score reduced antibiotic use by almost 30% and despite using fewer antibiotics, patients in the FeverPAIN score group experienced a greater improvement in symptoms. One in three patients in the FeverPAIN score group said their sore throat had improved rapidly from a moderately bad problem to a slight problem within two to four days. Moderately bad or worse symptoms also got better faster in the clinical score group.

However, the use of an in-practice rapid antigen test in conjunction with the FeverPAIN score did not result in any further reductions in antibiotic use or improvements in symptoms. The use of a rapid antigen test as well as the FeverPAIN test for patients who displayed streptococci symptoms did not offer any further improvements, with a 27% reduction in antibiotic use as well as similar improvements in patients' symptoms.

Michael Moore, MRCP, FRCGP, a coauthor of the study, said, “Clinicians can consider using a clinical score to target antibiotic use for acute sore throat, which is likely to reduce antibiotic use and improve symptom control. There is no clear advantage in the additional use of a rapid antigen test.” The study was published on October 10, 2013, in the journal British Medical Journal.

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University of Southampton
Inverness Medical