Clinical and laboratory features of the most common Clostridium difficile ribotypes isolated in Belgium.

Background: Previous studies comparing Clostridium difficile infection (CDI) due to different ribotypes have been conflicting, and many have only compared small numbers of cases or few ribotypes.

Aim: To compare patient and episode characteristics for CDI due to different ribotypes.

Methods: The ribotyping results from 3333 toxin-producing isolates collected from 110 Belgian hospitals between October 2010 and December 2015 were matched to clinical data from the national CDI surveillance database. Data for ribotypes with at least 100 occurrences were compared. In addition, the national reference laboratory quantitatively measured the level of toxin production in five randomly chosen cultured isolates for each of the most common ribotypes.

Findings: Ribotypes with more than 100 occurrences were R014, R020, R002, R078, R027, R005 and R106 (Brazier classification). The median age for all patients was 79 years [patients with R027, 83 years (P<0.001); patients with R106, 73 years (P<0.001)]. In total, 10% of episodes were recurrences; values were higher for R027 (22%) and R106 (18%). CDI due to R078 was not significantly more likely to be community associated than healthcare associated (28% vs 24%; P=0.1). Complications occurred in 7% of all episodes, and 12% for those with R027 and R078. However, after adjusting for age, onset outside the hospital and recurrence, R027 was no longer associated with complications [odds ratio (OR) 1.3, 95% confidence interval (CI) 0.7-2.4], unlike R078 (OR 1.7, 95% CI 1.0-2.6; P=0.04). A positive stool toxin test and greater levels of toxin production in the cultured isolates were more likely for R078 and R027.

Conclusion: Out of the seven most common ribotypes in hospital patients, R078 and R027 were associated with higher rates of complications. Infections with R027 and R106 were more likely to be recurrent. The presence of toxin in stools was most likely with R078, R027 and R106, with highest levels of toxin production in vitro for R078 and R027. R060 produced the lowest levels of toxin in vitro.