Pyogenic liver abscess caused by Pseudomonas aeruginosa: Clinical analysis of 20 cases

Background: There are few reports of Pseudomonas aeruginosa liver abscess (PALA) in the literature, and clinical information regarding its risk factors, route of transmission, and clinical course remains limited. Methods: The medical records of 1076 patients with pyogenic liver abscess treated at Chang Gung Memorial Hospital were reviewed. Results: Twenty of the patients whose records were analyzed had PALA. Mortality was 20%. Five patients with PALA, diagnosed immediately following an intra-abdominal surgical or endoscopic procedure, were classified as group A. The latent phase for the development of PALA in this group was less than 3 weeks. The remaining 15 patients were further subgrouped into group B (n = 8), with a traceable intra-abdominal procedure, and group C (n = 7), with no history of an invasive intra-abdominal procedure. The latent period in patients in group B varied from 6 weeks to 3.7 y. The absence of multidrug resistance in P. aeruginosa isolates from group C suggests the community-acquired nature of the infection in this group. Risk factor analysis showed that the incidence of hepatobiliary co-morbidities was high in all the groups (100%, 88%, and 71% in groups A, B, and C, respectively). The rates of co-infection with human gastrointestinal tract flora were 20%, 50%, and 71% in groups A, B, and C, respectively. Conclusions: PALA may be found in subjects without conventional risk factors for P. aeruginosa infection. In addition to patients with a preceding contaminated procedure, those with hepatobiliary co-morbidities form another high-risk group for this condition.