Demographics and Clinical Outcomes of Culture-Positive versus Culture-Negative Pyogenic Liver Abscess in an Asian Population

Objective: Despite its high case-fatality risk, pyogenic liver abscess (PLA) lacks clear management guidelines in patients with negative microbial cultures. Our aim was to evaluate differences in clinical characteristics between patients with culture-negative liver abscess (CNLA) and those with culture-positive liver abscess (CPLA), and identify differences in the main causative pathogen.Methods: In this study, we retrospectively collected medical records of PLA patients admitted to a teaching hospital from January 2010 to December 2019.Results: In total, 324 PLA patients were enrolled in this study. Of these, 202 (62.3%) cases were confirmed cultural positive, including 109 patients (54%) and 20 (9.9%) patients infected with Klebsiella pneumoniae (K. pneumoniae) and Escherichia coli (E. coli), respectively. Patients in the CPLA group were older (p=0.029) and had higher prevalence of abscesses larger than 5 cm in diameter (p = 0.003), gas-forming rate (p = 0.016), and percutaneous drainage (p < 0.001) compared with CNLA group. Patients with CPLA had significantly longer hospitalizations than those with CNLA (p = 0.010). Nevertheless, there was no significant difference in in-hospital mortality between the two groups (p = 0.415). Compared with patients with E. coli, those with K. pneumoniae had higher incidence of diabetes mellitus (p = 0.041), solitary abscess (p < 0.001), localization in the right hepatic lobe (p = 0.033), abscess size larger than 5 cm (p < 0.001) and percutaneous drainage (p = 0.002), but mortality was not significantly different (p = 1.000).Conclusion: No significant difference in in-hospital mortality was found between patients with CNLA and those with CPLA group. However, clinical characteristics and management were different between the main causative pathogens, including K. pneumoniae and E. coli.