Clostridium difficile infection (CDI) is a major cause of diarrhea and pseudomembranous colitis in acute and chronic care healthcare facilities. During the last decade, an increase in the incidence has been reported worldwide. This had been attributed to multiple factors including a more frail and older patient population, increased use of antibiotics that trigger the infection, and the emergence of virulent strains.
This report summarises the different sources of data available to describe the epidemiology of CDI in Belgium: epidemiological data from the mandatory surveillance scheme in hospitals including reference laboratory data (2007-2013), data on hospital discharges with a diagnostic of CDI (1999 -2011) and death registration data (1998-2010). The different sources of data confirm an important increase in CDI related incidence and mortality from 2002-2003 onwards. Mortality attained a peak in 2004, (linked particularly to an enormous increase in Brussels) subsequently followed by a decline. In 2010, the crude specific mortality rate for CDI in Belgium was 0.9 /100 000 inhabitants, highest in Brussels and lowest in Wallonia.
The peak in incidence around 2008 has diminished and stabilised in 2010-2011, but at an elevated level. In 2013, the mean CDI incidence for 105 hospitals contributing data the whole year was 1.65 episodes / 1000 admissions, the highest since 2009. The mean incidence of hospital acquired (HA) CDI (onset of symptoms > 2 days after admission in the declaring hospital) was 1.0 /1000 admissions (As a comparison, incidence of HA-MRSA, clinical samples, was 1.1/1000 admissions in 2012). The latest hospital surveillance data show a slight increase in the proportion of cases which are community-associated, as described in other countries. Incidence of HA CDI in 2013 was highest in Brussels and lowest in Flanders.
Other characteristics of cases have remained comparable to previous years – age, sex, the proportion of recurrences, the proportion thought to originate in long term care facilities.
The incidence is seasonal with a peak in March-April, and highly variable from one hospital to another, indicating an important potential for prevention.
Ribotyping of 585 CDI strains from 103 different hospitals in 2013 identified 133 different ribotypes, 72 of them isolated only once, 60 never identified before in Belgium. This illustrates the multiplicity of sources of transmission. The ribotypes most frequently isolated were ribotypes O14 (8% of total strains typed) and 020 (7%). The proportion of hospitals with the hypervirulent ribotype 027 decreased from 34% in 2009 to 15% in 2013. A decline in the prevalence of the ribotype 027 has been reported as well in the United Kingdom, and the Netherlands.
International comparisons indicate that Belgium has incidence rates of CDI in the mid-range of other European countries and lower than that in the United States. There are some indications that incidence of CDI is again rising in Europe, as it is in Belgium.