Evaluación de seis ensayos de PCR en combinación con los datos relacionados con el paciente para el diagnóstico de las infecciones asociadas a Clostridium difficile.

BACKGROUND:

The aim of this multicenter study was to establish a diagnostic algorithm using molecular methods for the diagnosis of C. difficile-associated infection (CDI). In addition patient specific data were taken into consideration for the interpretation of the results.

METHODS:

We compared the performance of six different commercially available PCR-tests, two toxin immunoassays, and a glutamat-dehydrogenase test by analysing liquid stool specimens from patients with suspected CDI. Toxigenic culture on CLO-agar was used as reference method.

RESULTS:

In total 250 stool specimens were collected at two study sites. 77 (30.8%) stool samples were culture-positive for toxigenic C. difficile. 173 (69.2%) specimens showed no growth of C. difficile. As a result, each of the PCR assays tested for C. difficile had a significantly higher sensitivity (94.8% - 100%) and NPV (97.6% - 100%) than the TOX-EIA with a sensitivity of 57.1% and NPV of 83.8%. Specificity of the PCR tests was 94.1% to 96.0% and PPV between 86.5% and 91.6%. The analysis of the patient data revealed a significant difference (p-value 0.0202) between toxin-positive and toxin-negative patients regarding prior antibiotic treatment, especially for cephalosporins.

CONCLUSIONS:

Our findings support the recommendation to restrict the use of antibiotics as a cornerstone in the prevention of CDI. We conclude that all of the PCR assays evaluated in this study can be applied in a diagnostic algorithm.