Diagnosis and antibiotic treatment of group a streptococcal pharyngitis in children in a primary care setting: impact of point-of-care polymerase chain reaction

Abstract

BackgroundTo compare the sensitivity and specificity of the recommended 2-step rapid antigen detection test (RADT) with confirmatory culture vs the point-of-care (POC) polymerase chain reaction (PCR) Roche cobas® Liat® Strep A test for detection of group A Streptococcus (GAS) in pediatric patients with pharyngitis, and to investigate the impact of these tests on antibiotic use in a large pediatric clinic.MethodsThis prospective, open-label study was conducted at a single site during fall/winter 2016–2017. A total of 275 patients aged 3 to 18 years with symptoms of pharyngitis had a throat-swab specimen analyzed using RADT, POC PCR, and culture. The sensitivity, specificity, and percentage agreement (95% CI) between assays and a laboratory-based nucleic acid amplification test were calculated. DNA sequencing was used to adjudicate discrepancies. The RADT or POC PCR result was provided to clinicians on alternating weeks to compare the impact on antibiotic use.ResultsA total of 255 samples were evaluated; 110 (43.1%) were GAS positive. Sensitivities (95% CI) for POC PCR, RADT, and culture were 95.5% (89.7–98.5%), 85.5% (77.5–1.5%), and 71.8% (62.4–80.0%), respectively. Specificities (95% CI) for POC PCR, RADT, and culture were 99.3% (96.2–99.98%), 93.7% (88.5–97.1%), and 100% (97.5–100%), respectively. Compared with RADT, POC PCR resulted in significantly greater appropriate antibiotic use (97.1% vs 87.5%; P = .0065).ConclusionUnder real-world conditions, RADT results were less specific and culture results were less sensitive than found in established literature and led to increased rates of inappropriate antibiotic use. POC PCR had high sensitivity and specificity and rapid turnaround times, and led to more appropriate antibiotic use.Trial registrationID number ISRCTN84562679. Registered October 162,018, retrospectively registered.

Appropriate Use and Future Directions of Molecular Diagnostic Testing

“…Group A Streptococcal (GAS) pharyngitis POC molecular tests are now CLIA-waved without the need for confirmatory culture of negative results. In a prospective primary care study comparing a CLIA-waved POC molecular test to conventional methods for GAS, Rao et al found a small but significant reduction in inappropriate antibiotic use for children presenting with symptoms of GAS pharyngitis [56]. For CT/NG, the majority of these tests are currently sent to central laboratories, leaving up to a 7-day waiting period from first visit to treatment.…”

Role of epidemiological risk factors in improving the clinical diagnosis of streptococcal sore throat in pediatric clinical practice

“…[12] Antibiotics are frequently prescribed for sore throat in developing countries, that in turn lead to huge healthcare expenditure and their irrational use may lead to antimicrobial resistance in the community. [34]…”

Organisation and quality monitoring for point-of-care testing (POCT) in Belgium: proposal for an expansion of the legal framework for POCT into primary health care

“…A recent study has shown that in realworld circumstances RADT results and laboratory cultures were less specific and sensitive than the literature has suggested, which has led to inappropriate antibiotic use. POCT based on NAATs (nucleic acid amplification techniques) on the other hand combines high sensitivity and specificity resulting in more efficient use of antibiotics in primary care settings in a US study [28]. However, like RADTs and throat culture, NAATs cannot by themselves discriminate between an infection and a carrier state.…”