BackgroundTo compare the efficacy of three antiseptic solutions [0.5%, and 1.0% alcohol/chlorhexidine gluconate (CHG), and 10% aqueous povidone-iodine (PVI)] for the prevention of intravascular catheter colonization, we conducted a randomized controlled trial in patients from 16 intensive care units in Japan.MethodsAdult patients undergoing central venous or arterial catheter insertions were randomized to have one of three antiseptic solutions applied during catheter insertion and dressing changes. The primary endpoint was the incidence of catheter colonization, and the secondary endpoint was the incidence of catheter-related bloodstream infections (CRBSI).ResultsOf 1132 catheters randomized, 796 (70%) were included in the full analysis set. Catheter-tip colonization incidence was 3.7, 3.9, and 10.5 events per 1000 catheter-days in 0.5% CHG, 1% CHG, and PVI groups, respectively (p = 0.03). Pairwise comparisons of catheter colonization between groups showed a significantly higher catheter colonization risk in the PVI group (0.5% CHG vs. PVI: hazard ratio, HR 0.33 [95% confidence interval, CI 0.12–0.95], p = 0.04; 1.0% CHG vs. PVI: HR 0.35 [95% CI 0.13–0.93], p = 0.04). Sensitivity analyses including all patients by multiple imputations showed consistent quantitative conclusions (0.5% CHG vs. PVI: HR 0.34, p = 0.03; 1.0% CHG vs. PVI: HR 0.35, p = 0.04). No significant differences were observed in the incidence of CRBSI between groups.ConclusionsBoth 0.5% and 1.0% alcohol CHG are superior to 10% aqueous PVI for the prevention of intravascular catheter colonization.Trial registrationJapanese Primary Registries Network; No.: UMIN000008725 Registered on 1 September 2012Electronic supplementary materialThe online version of this article (doi:10.1186/s13054-017-1890-z) contains supplementary material, which is available to authorized users.

We presented three cases of influenza-related severe pneumonia/empyema that occurred in one season.Case 1A 76-year-old diabetic man, developed empyema as a result of severe community-acquired pneumonia (CAP) secondary to Haemophilus influenzae, as confirmed on sputum culture. Nasal swab was positive for influenza A antigen. After drainage of empyema, intravenous peramivir and piperacillin/tazobactam were administered for 3 days and 2 weeks, respectively, followed by oral levofloxacin for 2 weeks. Eventually, he recovered. In this case, the isolated H. influenzae was non-typeable and negative for beta-lactamase.Case 2A 55-year-old man with suspected cerebral infarction and diabetes mellitus (DM) developed severe pneumonia/empyema as result of hospital-acquired pneumonia (HAP). Although influenza A antigen was detected, no bacterium was isolated from the sputum, blood, or pleural effusion. He showed severe hypoxia, but recovered after administration of peramivir and levofloxacin with prednisolone for 5 days and 2 weeks, respectively.Case 3A 76-year-old woman with heart failure and DM was followed-up on an outpatient basis and was under nursing home care for four months. Subsequently, she developed pneumonia and was admitted to our hospital; influenza antigen was isolated from nasal swab. Healthcare-associated pneumonia (HCAP)/empyema were diagnosed and were effectively treated with peramivir and levofloxacin for 4 days and 1 week, respectively.In diabetic patients, influenza virus may possibly accelerate pneumonia/empyema due to bacterial coinfection. Although non-typeable H. influenzae is a rare causative pathogen of empyema, it can be expected as a result of “pathogen shift” due to the increased use of the H. influenzae type b vaccine in Japan.