Prevalence of pleural effusion over eight years among Egyptian children in the delta region: a single center retrospective cross-sectional study

Abstract Background Pleural effusion (PE) is a significant clinical condition characterized by the accumulation of excess fluid in the pleural space, leading to respiratory distress and morbidity. In children, PE is commonly associated with pneumonia and respiratory infections. Despite its clinical importance, data on the prevalence and etiological factors of PE among pediatric populations in the Egyptian delta region are limited. This study is a trial to address this gap by evaluating the prevalence and clinical phenotyping of PE in children admitted to a tertiary care center in delta region. Methods A retrospective cross-sectional study was conducted at Mansoura University Children’s Hospital (MUCH), Egypt, from January 2016 to December 2023. Total hospital admissions aged 2 months to 18 years ( n = 19,411) were reviewed to identify cases of PE, parapneumonic effusion (PPE), and pneumonia for prevalence and phenotype analysis. Chest imaging was performed only when clinically indicated. Results The prevalence of Pleural effusion was 0.82% within this cohort, with infectious causes accounting for 83.13%. Pneumonia prevalence was 3.4% and parapneumonic effusion occurred in 19.96% in pneumonia cases. Clinical phenotyping revealed that the most common age group was 2–6 years (44.4%), with a male predominance (63.7%). The most frequent complication was loculation, observed in 13.8%. Staphylococcus coagulase-positive species were the primary isolates, found in 15.8% of pleural cultures and 14.4% of blood cultures. Lobar consolidation was seen in 43.8%. No documented pneumococcal vaccination through all the studied cases. In conclusion Pediatric pleural effusion in this region remains predominantly infection-related, with a high proportion of parapneumonic effusion (PPE). Our findings underscore the clinical importance of Staphylococcus species and the substantial morbidity associated with delayed care among children in Egypt’s Delta region. The absence of pneumococcal immunization further contributes to the disease burden. Strengthening vaccination programs, enhancing diagnostic infrastructure, and developing context-appropriate antimicrobial guidelines are essential steps to improve outcomes in resource-limited settings.