Estimating risk of C. difficile transmission from PCR positive but cytotoxin negative cases.

Autor: Kamboj M; Infection Control Program, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America ; Infectious Diseases Service, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America., Babady NE; Clinical Microbiology Service, Department of Laboratory Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America., Marsh JW; Division of Infectious Diseases, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America., Schlackman JL; Division of Infectious Diseases, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America., Son C; Infection Control Program, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America., Sun J; Infectious Diseases Service, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America., Eagan J; Infection Control Program, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America., Tang YW; Infectious Diseases Service, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America ; Clinical Microbiology Service, Department of Laboratory Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America., Sepkowitz K; Infection Control Program, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America ; Infectious Diseases Service, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America.
Jazyk: angličtina
Zdroj: PloS one [PLoS One] 2014 Feb 11; Vol. 9 (2), pp. e88262. Date of Electronic Publication: 2014 Feb 11 (Print Publication: 2014).
DOI: 10.1371/journal.pone.0088262
Abstrakt: Background: The use of molecular methods to diagnose Clostridium difficile infection (CDI) has improved diagnostic yield compared to conventional methods. However, PCR testing can detect colonization and has introduced several practical challenges pertaining to need for treatment and isolation of cases.
Methods: For all new cases detected by real-time PCR, concurrent cytotoxin assay was performed and genetic characterization with MLVA (multi-locus variable number tandem repeat analysis) was done to determine relatedness. We used PCR cycle threshold (Ct) of detection as surrogate marker for bacterial burden in stool.
Results: Overall, 54 cases of CDI were detected during the study period. 42 were concurrently tested by CYT and characterized by MLVA .MLVA analysis revealed marked genetic diversity with no ongoing outbreaks; four cases were due to NAP1 strain. CYT -/PCR + cases had a higher median Ct value of detection compared to CYT+/PCR + cases (28.2 vs 22.5; p = 0.01). Among 25 strains that were genetically related, 9/11 isolates in this dominant cluster were positive by CYT compared to 4/14 in non-dominant clusters (p = 0.02).
Conclusion: CYT-/PCR+ cases contribute to hospital based transmission. However, the risk of transmission of C. difficile from CYT +/PCR+ cases may be higher than those that are CYT-/PCR+.
Databáze: MEDLINE
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