Trends in mortality and morbidity related to Clostridium difficile infections, Belgium 1998-2007

Background
Clostridium difficile infection (CDI) incidence and mortality increased in North America and
Europe over the last decade. Emerging hypervirulent, fluoroquinolone-resistant strains might
have contributed to this. We measured CDI-related mortality, incidence and number of
diagnostic tests performed for the period 1998-2007, to assess the epidemiology of CDI in
Belgium.
Methods
We selected available data from: (1) mortality registries from Brussels, Flanders and
Wallonia regions, (1998-2007)-records with ICD-10 code for Clostridium difficile enterocolitis.
(2) from the Belgian hospital discharges database (1999-2007)-records with ICD-9-CM code
for intestinal CDI. (3) from the Belgian social security database (1998-2007)-the number of
CDI-related tests billed-. We calculated rates for mortality, hospital discharges and tests
performed. We standardized mortality and hospital discharge data by age, using Belgian
2000 midyear population and European Standard population for international comparisons.
We compared hospital discharge and diagnostic tests rate ratios.
Results
CDI-related crude mortality rate increased steadily since 1998 (0.1/100,000 inhabitants) in
Brussels and Flanders, to its peak in Brussels in 2004 (5.7/100,000 inhabitants) , and its
peak in Flanders in 2005 (1.3/100,000 inhabitants), and decreased in 2006 and 2007.The
oldest age-group (>=80years) was most affected. After standardization for age, rates appear
similar for men and women. Age-standardized rates of hospital discharge with a diagnosis
of CDI increased from 17.1 per 100,000 inhabitants in 1999, to 41.7 in 2007. Between 2000
and 2007 hospital discharges with CDI diagnosis increased by 240%, whereas diagnostic
tests performed in hospitals increased by 160%.Belgian standardized CDI-related mortality
rates were lower than those from other European countries and the US.
Conclusion
Both CDI-related mortality and morbidity have dramatically increased in Belgium between
1998 and 2007, especially in Brussels region. Mortality, but not morbidity, seems to be
decreasing in the last years studied.