Skin and Environmental Contamination in Patients Diagnosed With Clostridium difficile Infection but Not Meeting Clinical Criteria for Testing

Abstract

Of 134 patients diagnosed with Clostridium difficile infection, 30 (22%) did not meet clinical criteria for testing because they lacked significant diarrhea or had alternative explanations for diarrhea and no recent antibiotic exposure. For these patients, skin and/or environmental contamination was common only in those with prior antibiotic exposure.

Response to Prior and Fitzpatrick

“…We demonstrated that antibiotic-exposed patients not meeting criteria for CDI (ie, <3 unformed stools within 24 hours) were as likely to have skin and/or environmental contamination as CDI patients meeting criteria for testing. 1 Similarly, Biswas et al 8 demonstrated that fecal excretors frequently shed spores.…”

“…Although NAATs have excellent sensitivity, there is increasing concern that asymptomatic carriers of toxigenic C. difficile with unformed stool due to other causes (eg, laxatives) are often diagnosed with CDI, resulting in unnecessary treatment and inflation of CDI rates. [1][2][3][4][5] One strategy to address this concern has been to restrict testing to patients with 3 or more unformed stools within 24 hours. 5 Alternatively, a common approach in Europe is not to restrict testing but to use a 2-or 3-step testing algorithm in which results of stool toxin testing and clinical assessments are used to guide management for patients with positive initial screening assays for C. difficile.…”

Clostridium difficile—To Test or Not to Test? Response to Kundrapu et al

“…Although NAATs have excellent sensitivity, there is increasing concern that asymptomatic carriers of toxigenic C. difficile with unformed stool due to other causes (eg, laxatives) are often diagnosed with CDI, resulting in unnecessary treatment and inflation of CDI rates. [1][2][3][4][5] One strategy to address this concern has been to restrict testing to patients with 3 or more unformed stools within 24 hours. 5 Alternatively, a common approach in Europe is not to restrict testing but to use a 2-or 3-step testing algorithm in which results of stool toxin testing and clinical assessments are used to guide management for patients with positive initial screening assays for C. difficile.…”

“…Kundrapu et al 1 call for laboratories using stand-alone nucleic acid amplification tests for C. difficile testing to reduce testing of specimens that fail to meet clinical criteria, specifically patients with diarrhea without recent antibiotic exposure. In their study, a patient did not meet clinical criteria for testing if they had <3 unformed stools within 24 hours.…”

“…Notably, of the patients defined as 'not meeting clinical criteria for testing,' a significant proportion (37%) had received antibiotics within the previous 90 days, 1 which is a risk factor for CDI and should have prompted testing. As with many infections, CDI should be diagnosed on clinical grounds with laboratory results supporting the diagnosis, and not vice versa.…”