Table 2 This table illustrates differences among bacterial, amebic and Aspergillus liver abscesses
| Â | Bacterial | Amebic | Aspergillus |
|---|---|---|---|
Age | Older age | Middle age | Younger age |
Gender | Male predominant | Male predominant (7–10 times more common in adult men) | Male predominant |
Main risk factors | • Older age • Diabetes • Malnutrition | • Poor sanitation • Travel to endemic area • Oral and anal sex • Alcohol use | • Immunosuppression • Malignancy especially hematological e.g., ALL, AML • Organ transplant/bone marrow transplant |
Most common pathogens | Escherichia coli, Klebsiella spp, Streptococcus anginosus group, Staphylococcus aureus, and anaerobes | Entamoeba histolytica | Aspergillus spp |
Initial source of infection | • Biliary disease (50–60%) • Cryptogenic (35%) | Infection with E. histolytica cyst via fecal-oral transmission | • Cryptogenic (43%) • Primary lung infection with hematogenous spread (28%) • Intra-abdominal GI infection (19%) |
Clinical manifestations | • Fever • Abdominal pain • Constitutional symptoms • Jaundice • Septic emboli to eye, brain, meninges seen in Klebsiella BLA | • Fever • Abdominal pain • Constitutional symptoms • Concurrent diarrhea in < 1/3 of cases • Jaundice | • Fever • Abdominal pain • Constitutional symptoms • Coinfection with other pathogens (33%) |
Laboratory findings | • Leucocytosis common • LFTs derangement common • Increase in inflammatory markers (CRP, ESR) • In 30% blood cultures negative | • E. histolytica serology is useful to distinguish amoebic from BLA in non endemic regions • Serology can be negative in the 1st week of infection | • Galactomannan positive 57% • Blood cultures positive 11% |
Imaging characteristics | • Usually, multiple lesions in the right lobe of the liver • Abscess size < 10 mm in diameter • Septations are common • Gas within abscess: suspect Klebsiella spp | • Typically, solitary lesion • Subcapsular • Abscess size 5–10 cm (depends on the ALA form – chronic indolent abscesses are larger) • Most common location: the posterior part of the right lobe (70–80%) | • Solitary abscess (52%) • Multiple abscesses (48%) • Abscess size 2.2–9 cm |
Mortality | • Mortality 2.5–19% • Highest mortality in biliary origin compared to other causes • Higher risk of spontaneous rupture in Klebsiella BLA | • Mortality 1–3% • Excellent prognosis as they are very sensitive to antimicrobial medical therapy | • Mortality 38% |