Hospital-associated Clostridium difficile infections: First year results with National Healthcare Safety Network data, Los Angeles County, April 2010 – March 2011

Among healthcare-associated infections (HAIs), Clostridium difficile is the most common cause of infectious diarrhea with an estimated 2.8 cases/10,000 patient days. In 2008, California mandated hospital reporting of HAIs including C. difficile infections (CDI) through the National Healthcare Safety Network (NHSN). To determine relationships between CDI and hospital characteristics in Los Angeles County (LAC), we calculated CDI rates (per 10,000 patient days) from NHSN data during year one of reporting (April 1, 2010 - March 31, 2011) and compared medians with p-values based on Wilcoxon rank sum tests. Hospital-associated CDIs (HA-CDI) included hospital-onset cases (positive stool sample collected ≥4 days after admission) and community-onset-healthcare-facility-associated cases (positive stool sample ≤3 days after re-admission to the same hospital within four weeks of discharge). Hospital characteristics were obtained from self-reported profiles. 77 of 100 LAC hospitals had complete data. The median HA-CDI rate was 9.74 infections/10,000 patient days (range 0.0-113.2). Higher median HA-CDI rates existed for long-term acute care hospitals (LTAC) (n=7) than non-LTACs (n=70) (29.1 vs. 9.33, p<0.0001), non-trauma hospitals (n=64) versus trauma (n=13) (13.6 vs. 8.85, p=0.62), hospitals without emergency departments (ED) (n=16) versus those with EDs (n=61) (13.2 vs. 9.63, p=0.11), and hospitals with residency programs (n=15) versus those without (n=62) (10.9 vs. 9.33, p=0.17). Hospitals that used polymerase chain reaction as a CDI testing method (n=17) had a higher median hospital-onset CDI rate than those that did not (n=58) (8.54 vs. 6.55, p=0.04). Using NHSN data, health departments and local hospitals can collaborate in developing more targeted infection control of HA-CDI.