The results of 18 hospitals participating in the sentinel surveillance revealed that the mean incidence of CDI is 15 per 10.000 admissions, varying from 3 to 29 per 10.000 admissions. The incidence rates were not influenced by implementation of molecular tests to diagnose CDI, introduced in 2 laboratories. Among the 835 isolates cultured, type 001 was the most frequently found type (17%), type 014 was found in 13% and type 078 in 12%. Type 027 was found in 3% in seven hospitals. A total of 157 patients (27%) had severe CDI. After 30 days, 1 patient was admitted to the ICU as a consequence of CDI and 3 underwent a colectomy; 62 patients with CDI (13%) died. Eighteen deaths were contributable to CDI.
Extrapolating the data of sentinel surveillance to all hospitals in the Netherlands, it is estimated that more than 2700 hospitalized patients annually will develop CDI of which 100 will succumb attributable or contributable to CDI. In these estimations, the impact of CDI in other healthcare facilities than hospitals was not included. Therefore, the true number of patients with CDI admitted to healthcare facilities will be higher.
Between May 1st 2011 and May 1st 2012 twelve outbreaks were seen in the sentinel surveillance and two in the ad hoc typing.
In the period between May 1st 2011 and May 1st 2012, 289 samples from 26 healthcare facilities and laboratories in the Netherlands were investigated in the ad hoc typing. Type 001 and type 027 were the most commonly found PCR ribotypes (both in 15.0%), followed by type 078 (12.2%) and type 014 (11.4%). Type 027 was less frequently found compared to last year (26%), but still very common. Most of type 027 infections were found in one hospital with a large outbreak and a hospital with numerous type 027, this year not meeting the criteria of an outbreak. The largest outbreak due to type 027 took place in an elderly home.
The Reference Laboratory is now able to recognize and name 158 types. Additionally, 130 different unknown types were differentiated by the Reference Laboratory between 2005 and 2011. The Reference Laboratory is not yet able to name these isolates, therefore, 12 ’unknown’ types that occurred more than 5 times and were sent to the NHS Clostridium Reference Laboratory in Cardiff, Wales to name these isolates.
We conclude that type 027 is again a frequently found type in healthcare facilities that do not participate in the surveillance. This is due to two large outbreaks caused by this strain. Besides these outbreaks, the incidence seems stable, with types 001, 014 and 078 as the predominant types.