Pleuropneumonia caused by Group A Streptococcus (GAS)

In several parts of the world an increase in GAS infections has been reported, also in the context of complicated pneumonia. Data analysis from our hospital documented an increase in parapneumonic pleural effusion and empyema (PPE/PE) caused by GAS in the cohort of 2012-2020 (17%, manuscript in preparation) compared to 2006-2012 (0%, Proesmans M et al EJP 2014). Our aim was to assess the evolution of the incidence of GAS in PPE/PE. <bold>Methods:</bold> Children <18 years admitted to the Paediatric department of the University hospitals of Leuven between February 2022 and April 2023 were included. Data on bacterial aetiology combining bacterial culture (blood and pleural fluid) and PCR (pneumococcal PCR and 16S PCR and sequencing on pleural fluid) were retrospectively collected. <bold>Results:</bold> 48 children with PPE/PE were included of which 38 underwent a pleural punction/drain placement. Median age was 3years. GAS was the causative agent in 17/38 children (45%) (9 on pleural culture of which 2 also on blood culture, 1 on blood culture, 7 by 16S PCR only). In 8/38 (21%) a pneumococcus was detected (2 on pleural culture, 1 on blood culture, 8 by 16S PCR). PCR serogroups identified were 19 (n=3), 3 (n=2). In the remaining 13 no causative agent was found. However, in 12 of those 13 no pleural fluid was stored for 16S PCR analysis. <bold>Conclusion:</bold> The incidence (40/year) of PPE/PE was high compared to previous data from our centre (8-36/year between 2006-2012) with an increasing incidence of GAS PPE/PE. This may partially be explained by underdiagnosis in the past since 7 cases were only detected using 16S PCR and sequencing. PCR diagnostics can thus increase the yield of bacterial detection in PPE/PE improving epidemiological data and guided antibiotic treatment.