[Clostridioides difficile toxin B gen amplification cycle threshold as a predictor of severity]

Clostridioides dfficile infection (CDI) is the main cause of nosocomial diarrhea, generally associated with the use of antibiotics. This infection can cause uncomplicated diarrhea to pseudomembranous colitis or toxic megacolon. Recent studies have attempted to relate the threshold cycle (Ct) value of RT-PCR with mortality, as a fast, simple, objective and efficient method.

To evaluate Ct as a predictor of poor outcome in patients with C. dfficile disease with/without clinical signs of severity.

We carried out a retrospective study between January 2015 and December 2018, including all patients in the reference area of the Hospital Universitario de Canarias in Tenerife (396,483 inhabitants) in patients with clinical criteria of severity and patients without clinical severity criteria (according to the guide for the clinical practice of CDI of the Society of Healthcare Epidemiology of America (SHEA) and the Infectious Diseases Society of North America (IDSA).

A total of 202 CDI episodes were diagnosed. 77.7% (n = 157) presented clinical severity criteria. The presence of ulcerative colitis (p < 0.001), fever (p < 0.001), leukocytosis (p < 0.001), neutrophilia (p < 0.001), creatininemia (p = 0.005) were presented as risk factors for the development of severe CDI (S-CDI). Female sex, institutionalization, previous admission and death were described more frequently in the group with S-CDI, not finding significant differences. We found no differences with respect to the days of previous stay, or of post-CDI stay, although in the latter, the mean was higher in the case of S-CDI patients. No significant differences were found in terms of Ct in both groups; being only one point lower in patients with severity criteria (Ct = 26.1) than without severity criteria (Ct = 27.4) (p = 0.326). Conclusión: Based on the results of our study, it has not been possible to systematically implement the Ct value as a predictor of severity to the clinical report, and it is not possible to extrapolate this predictive variable from S-CDI and standardize the Ct value as a predictor of severity.

Basándonos en los resultados de nuestro estudio, no ha sido posible la implementación sistemática del valor Ct como predictor de gravedad al informe clínico, no siendo posible extrapolar esta variable predictora de enfermedad por C difficile-G y estandarizar el valor Ct como factor predictor de gravedad.