Pyogenic liver abscess as endemic disease, Taiwan

Abstract

Pyogenic liver abscess has become a health problem in Taiwanese society. However, the extent of this problem has remained unclear because of the lack of a population-based study. We therefore performed a nationwide analysis of pyogenic liver abscess in Taiwan from 1996 through 2004. We analyzed 29,703 cases from the Taiwan National Health Insurance database and 506 cases from National Taiwan University Hospital. Our analysis showed that the annual incidence of pyogenic liver abscess increased steadily from 11.15/100,000 population in 1996 to 17.59/100,000 in 2004. Diabetes, malignancy, renal disease, and pneumonia were associated with a higher risk for the disease. By contrast, death due to pyogenic liver abscess decreased over time, although population-based abscess-related death increased slightly. Renal disease, malignancy, pneumonia, and heart disease correlated with higher death rates; Klebsiella pneumoniae infection and therapeutic procedures were related to lower death rates. Diabetes did not significantly change death rates for the 506 patients from the hospital.

Figure 1

Number of new reported cases of pyogenic liver abscess recorded monthly in the National Health Insurance database, Taiwan, January 1996 through December 2004.

Figure 2

Incidence of pyogenic liver abscess in Taiwan, showing a steady increase from 1996 to 2004. The incidence is expressed as the number of new cases reported from the population (the National Health Insurance database) per year. A) The linear increase of the primary incidence data (raw incidence) with the year can be described by this formula: incidence (×1/100,000) = 0.860 × year – 1704.66 (r = 0.978, p<0.001). B) The linear increase of the standardized incidence data (the incidence normalized according to the age distribution of the population) with the year can be described by this formula: incidence (×1/100,000) = 0.512 × year – 1010.68 (r = 0.923, p<0.001). r, Pearson correlation coefficient.

Figure 3

Deaths from pyogenic liver abscess in Taiwan, showing a steady decrease from 1996 to 2004. Mortality rate is expressed as the number of deaths reported from pyogenic liver abscess cases per year. A) The linear decrease of the primary mortality data (raw mortality) with the year can be described with this formula: mortality (×1/100) = −0.314 × year + 639.58 (r = 0.910, p<0.001). B) The linear decrease of the standardized mortality data (the mortality normalized according to the age distribution of the population) with the year can be described with this formula: mortality (×1/100) = −0.383 × year +776.59 (r = 0.944, p<0.001). r, Pearson correlation coefficient. p<0.05 is considered statistically significant.