2185. Group A Streptococcus (GAS) Detection by PCR in Children with Viral Acute Respiratory Illness and Healthy Children

Abstract

Abstract Background Acute pharyngitis is mostly of viral etiology; GAS, the leading bacterial cause, comprises 20%–30% of pediatric pharyngitis. Patients with pharyngitis and additional acute respiratory illness (ARI) symptoms more suggestive of viral etiology, including cough, rhinorrhea and conjunctivitis, are not recommended for GAS testing. The use of highly sensitive GAS PCR assays in patients with sore throat and viral ARI symptoms may detect GAS colonization and lead to antibiotic overuse. We evaluated GAS PCR in viral ARI inpatients and asymptomatic healthy controls (HC) to illustrate the potential negative impact of offering GAS PCR test in poorly selected patients. Methods In November 2015–June 2016, 458 ARI inpatients (< 18 years) and 205 HC (< 5 years, no ARI symptoms within 72 hours) in Kansas City were enrolled in the New Vaccine Surveillance Network study. Mid-turbinate and throat swabs were tested by multiplex respiratory panel PCR and leftover nucleic acid extracts were further tested by real-time GAS PCR. Presenting symptoms of cough, rhinorrhea and/or conjunctivitis, plus sore throat were assessed by parent interview. Results Overall, 6.3% of HC < 5 years old and 8.7% of ARI subjects < 18 years were GAS (+); mostly in the 3–15 year old age group (25/40, 62.5%). Among 3–15 year old GAS (+) ARI subjects, 92.8% had cough, 76.2% rhinorrhea and 37.2% conjunctivitis; 80% had > 2 of 3 symptoms noted above. Among 40 GAS (+) ARI subjects, a virus was co-detected in 34 (85%), among which Rhinovirus/Enterovirus were predominant 22/34 (55%). Of the 130 (28%) ARI subjects with sore throat, more tested positive for viruses (107/130, 82.3%) than for GAS (9/130, 6.9%). All GAS (+) HC (13/205, 6.3% overall) were < 3 year olds. Conclusion PCR detected GAS in 6.3% HC < 5 years old and 8.7% ARI subjects < 18 years old; mostly in 3- to 15-year-old ARI subjects. Most GAS (+) ARI children had cough, rhinorrhea or conjunctivitis and/or virus co-detection suggesting GAS carriage. Our data demonstrate that GAS may be detected in patients with a low clinical suspicion for acute GAS pharyngitis. These findings highlight the need to review patient selection and exercise caution in implementing highly sensitive GAS PCR assays especially in such clinical settings. Disclosures All authors: No reported disclosures.