Is there any difference in pyogenic liver abscess caused by Streptococcus milleri and Klebsiella spp?: retrospective analysis over a 10-year period in a regional hospital.

Background/purpose: To compare the clinical characteristics of patients with Streptococcus milleri (SM) and Klebsiella spp. associated pyogenic liver abscess (PLA).

Methods: A retrospective study of patients with PLA due to SM and Klebsiella spp. was conducted. Clinical characteristics, laboratory and radiological features, management and outcomes were analyzed.

Results: From 2000 to 2009 inclusive, 21 and 140 patients had SM and Klebsiella spp. associated monomicrobial infected PLA, respectively. A higher incidence of active malignancy occurred in the SM group (14.3% vs. 3.6%, p < 0.03). The common clinical features of the patients were fever, chill and right upper quadrant pain. A longer duration (6.3 vs. 4.4 day, p = 0.04) of symptoms and a higher incidence of hepatomegaly (14.3% vs. 2.9%, p < 0.01) occurred in the SM group. Common laboratory and imaging abnormalities included: anemia, leukocytosis, high erythrocyte sedimentation rate and C-reactive protein, hypoalbuminemia, elevated total bilirubin and alanine aminotransferase, right hepatic lobe involvement, hypoechoic in ultrasonograpghy, rim enhancement and septal lobulation in computed tomography. The biliary tract disorder was the most common cause of the disease in the two groups. Patients with Klebsiella spp. associated PLA tended to have more complications: bacteremia (61.6% vs. 31.6%, p < 0.01) septic shock (33.6% vs. 19%, p = 0.11), disseminated intravascular coagulation (20.7% vs. 4.8%, p = 0.04), metastatic infections (10.7% vs. 0%, p = 0.06), acute renal and respiratory failure (5% vs. 0%, p = 0.14). However, both were effectively managed by the combination of antibiotics and image-guided aspiration with/without drainage, and their mortality rates were comparable to each other. Those patients with metastatic infection might need a longer duration (6.07 vs. 5.32 week, p = 0.144) of antibiotic therapy, which was due to the longer mean duration (3.85 vs. 2.86, p < 0.04) of an intravenous counterpart.

Conclusion: SM associated PLA tends to have a distinct clinical syndrome as compared with that of Klebsiella spp. with regard to risk factors, clinical manifestations and complications. However, both can be effectively treated with a combination of antibiotics and image-guided aspiration with/without drainage.