Reduced Clostridioides difficile infection in a pragmatic stepped-wedge initiative using admission surveillance to detect colonization.

BACKGROUND: Clostridioides difficile Infection (CDI) is a persistent healthcare issue. In the US, CDI is the most common infectious cause of hospital-onset (HO) diarrhea. OBJECTIVE: Assess the impact of admission testing for toxigenic C. difficile colonization on the incidence of HO-CDI. DESIGN: Pragmatic stepped-wedge Infection Control initiative. SETTING: NorthShore University HealthSystem is a four-hospital system near Chicago, IL. PATIENTS: All patients admitted to the four hospitals during the initiative. INTERVENTIONS: From September 2017 through August 2018 we conducted a quality improvement program where admitted patients had a peri-rectal swab tested for toxigenic C. difficile. All colonized patients were placed into contact precautions. MEASUREMENTS: We tested admissions who: i) had been hospitalized within two months, ii) had a past C. difficile positive test, and/or iii) were in a long-term care facility within six months. We measured compliance with all other practices to reduce the incidence of HO-CDI. RESULTS: 30% of admissions were tested and 8.3% were positive. In the year prior to the initiative (Period 1) there were 63,057 admitted patients when HO-CDI incidence was 5.96 cases/10,000 patient days. During the 12-month initiative (Period 2) there were 62,760 admissions and the HO-CDI incidence was 4.23 cases/10,000 patient days (p = 0.02). There were no other practice or antibiotic use changes. Continuing admission surveillance provided a HO-CDI incidence of 2.9 cases/10,000 patient days during the final 9 months of 2018 (p<0.0001 compared to Period 1), equaling <1 case/1,000 admissions. LIMITATIONS: This was not a randomized controlled trial, and multiple prevention practices were in place at the time of the admission surveillance initiative. CONCLUSION: Admission C. difficile surveillance testing is an important tool for preventing hospital-onset C. difficile infection. REGISTRATION: This quality improvement initiative is registered at ClinicalTrials.gov. The unique registration identifier number is NCT04014608.

Dose-ranging study to assess the application of intranasal 2% mupirocin calcium ointment to eradicate Staphylococcus aureus nasal colonization.

BACKGROUND: Mupirocin nasal ointment may be prescribed for decolonization prior to surgical procedures, especially for carriers of methicillin-resistant Staphylococcus aureus (MRSA). The approved regimen for decolonization of S. aureus from the anterior nares is twice daily for 5 d (10 doses). We performed a two-center, randomized, open-label study to compare the utility of six and 10 doses for decolonization of S. aureus. METHODS: Patients expecting to undergo surgery were screened for S. aureus nasal carriage approximately three weeks prior to the procedure. Those found to be positive were offered enrollment in the study. In the first arm (n=41), patients were randomized to receive 2, 3, or 5 d (six or 10 doses) of treatment prior to their operation. Their anterior nares were swabbed for culture and S. aureus polymerase chain reaction (PCR) during the decolonization therapy period as well as for four weeks after surgery. In the second arm (n=60), all patients were given 5 d (10 doses) of nasal mupirocin treatment, and the patient's anterior nares were swabbed for culture and S. aureus PCR for four weeks after surgery. Data from six of the patients were excluded from analysis because of failure to submit swabs after operation. All S. aureus isolates were tested for susceptibility to mupirocin and the presence of the mecA gene to detect MRSA. RESULTS: In Arm 1, 16 patients received 10 doses of mupirocin, 18 received six doses (twice daily for 3 d), and 7 received six doses (thrice daily for 2 d). In the second arm, all patients received 10 doses of mupirocin (twice a day for 5 d). Overall, 89.5% patients who received 10 doses of mupirocin remained decolonized for at least four weeks after surgery versus 68.0% of patients who received six doses (p=0.016). There was no difference between arms 1 and 2 for those given mupirocin twice daily for 5 d. CONCLUSION: The ten-dose regimen is superior to any six-dose regimen for de-colonizing S. aureus from the anterior nares of patients and for maintaining the decolonized state for at least four weeks after therapy.

Performance of the BD GeneOhm methicillin-resistant Staphylococcus aureus test before and during high-volume clinical use.

We evaluated the use of the BD GeneOhm MRSA real-time PCR assay (BD Diagnostics, San Diego, CA) for the detection of nasal colonization with methicillin-resistant Staphylococcus aureus (MRSA). The initial evaluation consisted of 403 paired nasal swabs and was done using the specimen preparation provided with the kit and an in-house lysis method that was specifically developed to accommodate large-volume testing using a minimal amount of personnel time. One swab was placed in an achromopeptidase (ACP) lysis solution, and the other was first used for culture and then prepared according to the kit protocol. PCR was performed on both lysates, and results were compared to those for culture. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the PCR assay were 98%, 96%, 77%, and 99.7% with the kit lysate and 98%, 95%, 75%, and 99.7% with the ACP lysate (P, not significant), respectively. The second evaluation was done after implementation of all-admission surveillance using PCR with ACP lysis and a sampling of 1,107 PCR-negative samples and 215 PCR-positive samples that were confirmed by culture. The results of this sampling showed an NPV of 99.9% and a PPV of 73.5% (prevalence, 6%), consistent with our initial findings. The BD GeneOhm MRSA assay is an accurate and rapid way to detect MRSA nasal colonization. When one is dealing with large specimen numbers, the ACP lysis method offers easier processing without negatively affecting the sensitivity or specificity of the PCR assay.