Increasing incidence of candidemia: results from a 20-year nationwide study in Iceland

Abstract

A nationwide study on candidemia was conducted in Iceland from 1980 to 1999. The annual incidence increased from 1.4 cases/100,000 inhabitants/year between 1980 and 1984 to 4.9 cases/100,000 inhabitants/year between 1995 and 1999 (P < 0.0001). Candidemia episodes at university hospitals increased from 0.15/1,000 admissions to 0.55/1,000 admissions (P < 0.0001). Candida albicans was the predominant species responsible (64.4%). The national import of fluconazole increased approximately fourfold during the second half of the study, but increased resistance to this agent was not observed.

FIG. 1.

Increasing incidence (cases/100,000 inhabitants/year) of candidemia in Iceland during a 20-year period, from 1980 to 1999. The open squares with solid lines represent the population-based incidence, whereas the filled squares with dashed lines depict the incidence as a proportion of 1,000 admissions to the university hospitals in the country. As shown, the nationwide incidence increased 3.5-fold during the 20 years of the study, from 1.4 between 1980 and 1984 to 4.9 between 1995 and 1999 (P < 0.0001). The number of candidemic episodes per 1,000 admissions at the two university hospitals also increased significantly, from 0.15/1,000 admissions between 1980 and 1984 to 0.55/1,000 admissions between 1995 and 1999 (P < 0.0001).

FIG. 2.

Age-specific incidence of fungal BSIs in Iceland from 1980 to 1999 calculated for the first and second decades of the study. As shown, the age-specific incidence was similarly distributed in the first (open circles, solid lines) and the second (filled circles, dashed lines) decades, with the exception of the youngest age group (<1 year old). The incidence was low in people aged 5 to 40 years but started to rise among people aged 41 to 50 years. Incidence subsequently increased with advancing age, peaking among patients aged 61 to 70 years (1980 to 1989, 12.7 cases/100,000 inhabitants/year; 1990 to 1999, 19.3 cases/100,000 inhabitants/year). From 1980 to 1989, no children of <1 year of age were diagnosed with candidemia. After 1989, however, the incidence followed a biphasic pattern, with a high incidence occurring in the youngest age group (<1 year, 11.3 cases/100,000 inhabitants/year). Most of the children younger than 1 year old were preterm infants in the neonatal ICU at the time of diagnosis.