When should clinicians suspect group A streptococcus empyema in children? A multicentre case-control study in French tertiary care centres

Background The incidence of invasive group A streptococcus (GAS) infections is increasing worldwide, whereas there has been a dramatic decrease in pneumococcal invasive diseases. Few data describing GAS pleural empyema in children are available. Objective To describe the clinical and microbiological features, management and outcome of GAS pleural empyema in children and compare them with those of pneumococcal empyema. Design, setting and patients Fifty children admitted for GAS pleural empyema between January 2006 and May 2013 to 8 hospitals participating in a national pneumonia survey were included in a descriptive study and matched by age and centre with 50 children with pneumococcal empyema. Results The median age of the children with GAS pleural empyema was 2 (range 0.1-7.6) years. Eighteen children (36%) had at least one risk factor for invasive GAS infection (corticosteroid use and/or current varicella). On admission, 37 patients (74%) had signs of circulatory failure, and 31 (62%) had a rash. GAS was isolated from 49/50 pleural fluid samples and from one blood culture. The commonest GAS genotype was emm1 (n = 17/22). Two children died (4%). Children with GAS empyema presented more frequently with a rash (p < 0.01), signs of circulatory failure (p = 0.01) and respiratory disorders (p = 0.02) and with low leucocyte levels (p = 0.04) than children with pneumococcal empyema. Intensive care unit admissions (p < 0.01), drainage procedures (p = 0.04) and short-term complications (p = 0.01) were also more frequent in patients with GAS empyema. Conclusions Pleural empyema following varicella or presenting with rash, signs of circulatory failure and leucopenia may be due to GAS. These features should prompt the addition to treatment of an antitoxin drug, such as clindamycin.