2179. Detection of Group A Streptococcus in the Saliva of Children Presenting With Pharyngitis Using the cobas®LIAT® PCR System

Abstract

Background

CLIA waived polymerase chain reaction (PCR) has recently become available as a point of care test for Group A Streptococci (GAS) in individuals presenting with pharyngitis, enabling rapid and accurate diagnosis. However, swabbing the pharynx results in discomfort and is often dreaded by young children which may result in poor quality sampling.

Objective

In order to assess the viability of saliva as a sample specimen for GAS, this study compared saliva samples with pharynx swabs of children with sore throat, using swabs inoculated by children sucking on them as they would a lollipop in the context of newly available very sensitive techniques.

Methods

We enrolled children ages 5–15 years presenting with sore throat and known to have a positive rapid streptococcal antigen detection test (RADT) performed on a posterior pharyngeal swab, at the discretion of the primary care provider. The RADT used was the SureVue® (Fisher Scientific) system. A second swab was obtained by having the child suck on the swab in the anterior mouth for 30 seconds and a third swab was obtained from the posterior pharynx. PCR was performed on these two additional swabs using the cobas®LIAT® (Roche) system according to the manufacturer’s instructions.

Results

Seventeen children were enrolled in the study between January and April 2019. The mean age of enrollment was 9.6 years (range 6–15). By design all children were known to have a positive RADT for GAS. The LIAT posterior pharynx swab was positive in all 17 subjects. In addition, the LIAT saliva swab was positive in all 17 subjects.

Conclusion

In this small pilot study, there was 100% concordance between the RADT for GAS and both the posterior pharyngeal and saliva swab using the cobas®LIAT® PCR system. Performing saliva swabs will result in less discomfort and distress to children who are tested for GAS. Further study is needed to determine the sensitivity and specificity of saliva swabs for the detection of GAS in children presenting with acute pharyngitis.

Disclosures

All authors: No reported disclosures.