title: Three-step diagnostic algorithm in diagnosing patients suspected of Clostridium difficile-associated diarrhea.
abstract: Clostridium difficile is a predominant etiological agent of healthcare-associated infectious diarrhea. Immunoenzymatic tests for detecting toxins A/B from faecal samples are still used in routine diagnosis of Clostridium difficile-associated diseases in a number of healthcare centers in Poland. Recently, however, new diagnostic tests were introduced which allow for detecting toxigenic strains of C. difficile in a more effective and precise manner. It is of importance, especially in the light of hypervirulent strain occurrence.
  
  
  OBJECTIVE
  The aim of the present paper was to evaluate the efficacy of three-step algorithm in the diagnosis of Clostridium difficile-associated diseases (CDAD), considering the occurrence of false negative test results for toxins while using exclusively immunoenzymatic tests.
  
  
  METHODS
  In the present study, faecal samples collected from patients presenting diarrhea were tested. Immunoenzymatic tests were used for detecting glutamate dehydrogenase (GDH) and toxins A/B. Culture and RT-PCR were also employed.
  
  
  RESULTS
  Of 615 study participants, toxigenic strains GDH (+) TOX (+) were identified in 108 patients while for 67 patients, test results remained unspecified GDH (+) TOX (-). Further analysis of unspecified samples revealed 32 patients infected with toxigenic strains, i.e. 22.9% of all positive test results (n=140).
  
  
  CONCLUSIONS
  Three-step diagnostic algorithm is an effective and reliable tool for diagnosing C.difficile- associated diseases.
authors.affiliation: Microbiology Clinical Laboratory.
authors.forename: Anna
authors.initials: A
authors.lastname: Schneider
authors.affiliation: Microbiology Clinical Laboratory.
authors.forename: Anna
authors.initials: A
authors.lastname: Mól
authors.affiliation: Microbiology Clinical Laboratory.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Lisowska
authors.affiliation: Section for Healthcare-associated Infection Control University Hospital of Lord's Transfiguration in Poznań
authors.forename: Maria
authors.initials: M
authors.lastname: Jax-Dambek
authors.affiliation: Department of Medical Microbiology, Warsaw Medical University.
authors.forename: Dominika
authors.initials: D
authors.lastname: Lachowicz
authors.affiliation: Department of Medical Microbiology, Warsaw Medical University.
authors.forename: Piotr
authors.initials: P
authors.lastname: Obuch-Woszczatyński
authors.affiliation: Department of Medical Microbiology, Warsaw Medical University.
authors.forename: Hanna
authors.initials: H
authors.lastname: Pituch
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001426:Bacterial Proteins / Q000302:isolation & purification*; D001427:Bacterial Toxins / Q000302:isolation & purification*; D016360:Clostridioides difficile / Q000302:isolation & purification; D003967:Diarrhea / Q000382:microbiology*; D004761:Enterocolitis, Pseudomembranous / Q000175:diagnosis* / Q000382:microbiology; D004768:Enterotoxins / Q000302:isolation & purification*; D005243:Feces / Q000737:chemistry*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008875:Middle Aged; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004768:Enterotoxins; C041348:tcdA protein, Clostridium difficile; C031815:toxB protein, Clostridium difficile