Diagnostic Utility of Pleural Infection-specific Multiplex PCR Panel

Pleural effusion is a common cause of hospitalization. Pleural infection ranked third among the pleural effusions requiring hospitalization in the United States. Pleural infection, including complicated parapneumonic effusion and empyema, is associated with a 30-day mortality of 10%. Approximately 20-57% of patients with pneumonia have an associated pleural effusion at presentation, of which 5-7% progress to pleural infection. Analyses of several nation-wide healthcare databases in the United States, France and the United Kingdom have showed an increasing incidence of pleural infection in the past decade. Adequate antibiotic coverage and fluid drainage are the two pillars of treatment for pleural infection. The empirical use of antibiotics should be based on the local spectrum of causative microorganisms and the source of infection. Subsequent targeted antibiotic regimen can be guided by the culture results and sensitivity pattern of the cultured microorganisms. The use of blood culture bottles as the transfer medium can improve the culture positivity from 30-40% to 60%. An explorative study of culturing pleural tissue can increase the microbiological yield from 20% to 45%. Despite these methods, the culture positivity rates are far from 100% although clinical evidence of pleural infection. Peripheral blood cultures may occasionally be the only positive source of culture (12%). Occasionally, complicated malignant pleural effusion (MPE) can mimic pleural infection, by sharing similar biochemical features of high neutrophil counts and lactate dehydrogenase in the pleural fluid. This would subject the patients with MPE to unnecessary prolonged course of antibiotic and delay of chemotherapy. Prolonged course of broad-spectrum antibiotics (BSA) is commonly required for culture-negative pleural infection or MPE with complicated features, but it could lead to various antibiotic-related adverse events, including kidney and liver injuries, opportunistic infections (e.g. Clo