Viral Features and Testing for Streptococcal Pharyngitis.

BACKGROUND AND OBJECTIVES: The Infectious Diseases Society of America recommends that clinicians forego testing for group A Streptococcal (GAS) pharyngitis in patients with clinical features of viral illness. The prevalence of viral features in patients tested for GAS pharyngitis is not known. The objectives of this study were as follows: to describe the prevalence of viral features in pediatric patients for whom rapid antigen detection tests (RADTs) for GAS pharyngitis are performed; and to compare the prevalence of GAS and the sensitivity of the RADT in patients with and without viral features.

METHODS: This secondary analysis of data from a prospective cohort study included children aged 3 to 21 years for whom RADTs were performed for sore throat in an urban tertiary care emergency department. The primary outcome was the prevalence of viral features, defined as cough, rhinorrhea, oral ulcers/vesicles, and/or conjunctival injection. Secondary outcomes were the prevalence of GAS and sensitivity of the RADT; these outcomes were compared between patients with and without viral features.

RESULTS: Overall, 63% (95% confidence interval [CI]: 57%-68%) of patients had at least 1 viral feature. The prevalence of GAS pharyngitis was higher in patients without viral features (42% [95% CI: 33%-51%]) than in patients with viral features (29% [95% CI: 23%-35%]) ( P = .01). The sensitivity of the RADT was 84% (95% CI: 77%-91%) and was not significantly different in patients with and without viral features.

CONCLUSIONS: Because many asymptomatic children are carriers of GAS, judicious use of laboratory testing for GAS pharyngitis remains an important target for antimicrobial stewardship.