Objectives: To assess the reliability and validity of a rapid test for the identification of Streptococcus pyogenes in the pharyngeal exudate of children presenting with pharyngotonsillitis. To evaluate the impact of its use in outpatient clinics on antibiotic use, on the incidence of second medical visits and complications, and on the degree of parental satisfaction.
Patients and methods: After a clinical diagnosis of acute pharyngitis was established and written informed consent obtained from the parents, dual throat swabs were collected from 430 children who attended the emergency department of our hospital or the pediatric offices of three health centers in our area. The first specimen was examined by the rapid test, QuickVue Flex Strep A, and the second one was sent to the laboratory for conventional culture. As a rule, antibiotics were indicated only when the rapid test was positive. Special emphasis was placed on explaining to parents that treatment was not necessary when the test was negative. Telephone follow-up was provided to the family during the next four weeks, after which a satisfaction survey was carried out.
Results: The sensitivity of the investigated rapid test was 91.2% (negative predictive value: 96.5%) and specificity was 96.2% (positive predictive value: 90.4%). Antibiotics were given to 41.9% of the patients, approximately half the expected rate in the absence of the rapid test. There was no significant difference in the number of second visits or hospitalizations between the groups of treated and non-treated subjects. Clinical evolution was good in all cases. The degree of parental satisfaction was very high, independent of the treatment given to the patients.
Conclusions: The rapid test for the detection of group A streptococci is a reliable tool for the selection of patients able to benefit from antibiotic treatment. It is easy to handle and apply and its use allows a significant reduction in the administration of antibiotics in pharyngotonsillitis. Most users accept and are satisfied with this novel diagnostic and therapeutic procedure.