Pyogenic liver abscess and the emergence of Klebsiella as an etiology: a retrospective study

OBJECTIVES Pyogenic liver abscess (PLA) is a significant, though uncommon, cause of morbidity in the United States. Recently, Klebsiella has emerged as an important cause of PLA. We analyzed the clinical course, microbiology, and treatment outcomes of patients discharged with PLA. In addition, we sought to examine the incidence of and risk factors for Klebsiella liver abscess (KLA). METHODS We reviewed the charts of patients who discharged with PLA from two teaching hospitals in West Texas between January 1, 2007 and December 31, 2011. RESULTS We identified 49 cases of PLA. Abscess cultures were positive in 23 (48%) patients. The mean age of the cohort was 56 years (range: 20-83 years). Sixty percent were male. The most frequent conditions associated with PLA were intra-abdominal infections (ten cases; 20%), diabetes mellitus (nine cases; 18%) and malignancy (nine cases; 18%). Klebsiella was the most commonly isolated species from the abscess cultures (seven cases; 30% of all positive abscess cultures). We used univariate and logistic regression analyses to identify the risk factors for KLA. Controlling for age, only malignancy was identified in our cohort as a risk factor for a Klebsiella liver abscess. The overall mortality was 2%. CONCLUSION Klebsiella is emerging as an important cause of liver abscesses. Malignancy may be an important risk factor for Klebsiella liver abscess.