Streptococcus pyogenes infection in paediatrics: from pharyngotonsillitis to invasive infections

Abstract

Abstract Background Streptococcus pyogenes or Group A Streptococci (GAS) cause many infections in infancy. Changes in its epidemiology have been described in recent years, including an increase in invasive infections (iGAS). Methods A retrospective-descriptive study was conducted on children less than 15-years-old, with GAS infections, in particular iGAS, and their complications from February 2004 to April 2014. Results A total of 2192 positive cultures were obtained of which 92.7% were pharyngeal cultures. Twenty-nine patients were admitted to hospital: 4 with suppurative complications, 7 post-infective, 14 iGAS, and 4 probable iGAS cases. There were no differences in the frequency of GAS isolations/year. Non-invasive isolates were more frequent in winter and spring (P The incidence of iGAS was 2.1/100 000 children/year. There was no seasonality, and it was more frequent in younger children (P = .039). The most common diagnosis was pneumonia (6/14). Eight patients required intensive care. They were treated empirically with second or third-generation cephalosporin or with intravenous penicillin, and pneumonia required longer treatment times (P = .016). All GAS isolates were sensitive to penicillin, and 10.6% were resistant to erythromycin. The time spent in hospital was longer for iGAS than other cases (P = .028). No patients died. Conclusions Pharyngotonsillitis caused by GAS is common in childhood, and its incidence is increasing in children younger than 5 years. At the moment, post-infectious complications are rare. Invasive infections are the most severe forms of presentation, and are more common in younger children.