Spectrum of gallstone disease in the veterans population

Elderly male patients are thought to have a higher incidence of biliary infections. This demographic is common among veterans, so we analyzed the spectrum of gallstone disease in a large veteran population.

A total of 285 patients with gallstone disease were studied. There were 27 women and 258 men, with an average age of 62 years. Gallstones, bile, and blood (as indicated) were cultured. Illness severity was staged as none (no clinical infection), moderate (fever, leukocytosis), or severe (cholangitis, bacteremia, abscess, hypotension, organ failure). Gallstones were grouped by appearance. Three bacterial groups were defined: EK (Escherichia coli or Klebsiella species), N (Enterococcus), or Oth (all other species).

Biliary bacteria were present in 145 (51%) patients. Bacterial presence by patient age was 33% for those less than 50 years, 48% for those 50 to 70 years, and 65% for those more than 70 years (P <.02 vs. others). Bacterial presence by stone type was as follows: cholesterol, 11%; mixed, 51%; pigment, 71% (P <.01 vs. others). Illness severity by stone type was as follows for cholesterol: none, 73%; moderate, 27%; severe, 0%; for mixed: none, 62%; moderate, 25%; severe, 13%; for pigment: none, 41%; moderate, 17%; severe, 41% (P <.0001 vs. others). Illness severity by bacterial group was as follows for sterile: none, 77%; moderate, 23%; severe, 0%; for the Oth group: none, 57%; moderate, 22%; severe, 20%; for the N group: none, 32%; moderate, 16%; severe, 52%; for the EK group: none, 18%; moderate, 22%; severe, 60% (P <.0001 vs. sterile/Oth, P = .126 vs. N).

Bacterial biliary tree colonization is prevalent in the veterans' population, it increases with age, and is more common with pigment stones. But not all bacterial species cause infectious manifestations. Patients with E coli and/or Klebsiella species commonly showed infectious manifestations, patients with Enterococcus were in an intermediate range, and those with other species had few infectious manifestations.