Health care-associated bloodstream infections associated with negative- or positive-pressure or displacement mechanical valve needleless connectors.

BACKGROUND: Health care-associated, central venous catheter-related bloodstream infections (HA-BSIs) are a major cause of morbidity and mortality. Needleless connectors (NCs) are an important component of the intravenous system. NCs initially were introduced to reduce health care worker needlestick injuries, yet some of these NCs may increase HA-BSI risk. METHODS: We compared HA-BSI rates on wards or intensive care units (ICUs) at 5 hospitals that had converted from split septum (SS) connectors or needles to mechanical valve needleless connectors (MV-NCs). The hospitals (16 ICUs, 1 entire hospital, and 1 oncology unit; 3 hospitals were located in the United States, and 2 were located in Australia) had conducted HA-BSI surveillance using Centers for Disease Control and Prevention definitions during use of both NCs. HA-BSI rates and prevention practices were compared during the pre-MV period, MV period, and post-MV period. RESULTS: The HA-BSI rate increased in all ICUs and wards when SS-NCs were replaced by MV-NCs. In the 16 ICUs, the HA-BSI rate increased significantly when SS-NCs or needles were replaced by MV-NCs (6.15 vs 9.49 BSIs per 1000 central venous catheter [CVC]-days; relative risk, 1.54; 95% confidence interval, 1.37-1.74; P < .001). The 14 ICUs that switched back to SS-NCs had significant reductions in their BSI rates (9.49 vs 5.77 BSIs per 1000 CVC-days; relative risk, 1.65; 95% confidence interval, 1.38-1.96; p < .001). BSI infection prevention strategies were similar in the pre-MV and MV periods. CONCLUSIONS: We found strong evidence that MV-NCs were associated with increased HA-BSI rates, despite similar BSI surveillance, definitions, and prevention strategies. Hospital personnel should monitor their HA-BSI rates and, if they are elevated, examine the role of newer technologies, such as MV-NCs.

Analysis of an outbreak of Clostridium difficile infection controlled with enhanced infection control measures.

BACKGROUND: In October 2004, our Clostridium difficile infection (CDI) rate increased (relative risk, 3.51; 95% confidence interval: 2.96-4.16) from a baseline rate of 1.35 per 1000 patient-days. We describe the outbreak, the relationship between antibiotic use and CDI, and the effect of enhanced infection control measures (EICM) on CDI. METHODS: Rates were calculated as positive C difficile toxin A or B tests among patients with nosocomial diarrhea per 1000 patient-days (duplicates removed). Antibiotic use was calculated as defined daily dose per 1000 patient-days. EICM consisted of (1) placing patients with diarrhea into empiric Contact Precautions, (2) cleaning with a bleach product in areas with CDI patients, and (3) requiring soap and water hand hygiene when caring for CDI patients. CDI rates were analyzed by chi(2) for trend. Time series methodology was used to examine the association between CDI and antibiotic use. RESULTS: During the outbreak (October 2004-May 2005), we observed 144 excess cases of CDI. The CDI rate decreased after EICM were implemented (P < .0001) and has been maintained for 36 months beyond the outbreak. Multivariate analysis revealed positive associations between CDI rates and cefazolin use (P = .008) and levofloxacin/gatifloxacin use (P = .015). CONCLUSION: Despite an association between some antibiotic use and CDI rates, we achieved sustained control of an outbreak using EICM without formulary changes or new antibiotic control policies. This suggests that patient-to-patient spread may be a more important cause of increased CDI rates.