Pyogenic liver abscess: diagnosis, bacteriology and treatment.

Pyogenic liver abscess is an uncommon but potentially fatal disease. The accuracy of diagnosis made on clinical grounds can now be greatly improved with the use of modern organ-imaging techniques. The condition is often polymicrobial: Escherichia coli and other enteric gram-negative rods are major pathogens, with anaerobic gram-negative rods and Streptococcus milleri being increasingly recognised. Staphylococcal liver abscesses are less common, often arising in association with neutrophil disorders. Open surgical drainage along with antimicrobial chemotherapy has long been regarded as standard treatment, however, in many centres it is being displaced by percutaneous drainage under the guidance of computed tomography or ultrasound. Some patients have been successfully treated with antimicrobial chemotherapy alone. Once specimens have been taken for culture, empiric antimicrobial therapy should include a combination of an anti-anaerobe agent, an aminoglycoside and a beta-lactam drug such as ampicillin. Early diagnosis and treatment of this condition is essential for patient survival.