Microbiology of Liver Abscesses and Its Correlation with Hospital Stay

Abstract

Pyogenic liver abscess (LA) is a rare disease associated with high morbidity and mortality rates, and prolonged hospital stay. Certain microbiological agents have assumed a predominant role in Asian series, however, few studies have been published in Europe regarding the microbiological agents involved in liver abscesses and their relationship with prognosis and length of hospital stay. The aim of this study was to characterize the main microbiological agents involved in LA in a European hospital, to assess resistance patterns and to relate them to patient prognosis and length of hospital stay. A retrospective analysis was conducted on all LA-diagnosed adult patients, admitted to a northern Portuguese hospital between 2013 and 2018. Clinical, laboratory, imaging, and microbiological data were collected for descriptive and statistical analysis. A total of 63 LA diagnosed patients were admitted to the General Surgery Unit between January 2013 and December 2018. Patients´ mean age at diagnosis was 71.4 years. Abdominal pain and fever were the most common symptoms on admission (73.0 and 61.9%, respectively). Fifty-eight percent of patients were female. Leukocytosis and increased C-reactive protein were the most observed analytical changes. The most frequently isolated microbiological agents were <i>Escherichia coli</i> (36.5%), <i>Streptococcus species</i> (27.8%), <i>Klebsiella pneumoniae</i> (11.4%), and anaerobic agents (10.1%). Of the isolated species, 12.5% proved multi-resistant. A higher LA frequency caused by <i>Klebsiella pneumoniae</i> was identified in relation to other Western series. <i>Klebsiella pneumoniae</i> was associated with a longer hospital stay (25.67 vs 16.50 days, p=0.07) when compared to other agents. There were 4 mortality cases in our series (6.3%). Microbiological agents, namely <i>Klebsiella pneumoniae</i> and multidrug-resistant agents have a predominant role in LA management, negatively affecting prognosis and length of hospital stay. Despite advances in LA treatment, more studies are required to determine the appropriate therapy owing to the absence of internationally defined guidelines. Our results provide important information for the proper management of these patients.